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Background It has been demonstrated that reference to the past is difficult for individuals with agrammatic aphasia, leading to the formulation of the PAst DIscourse LInking Hypothesis (PADILIH). Many of the previous studies have focused on Indo-European languages, in which time reference is expressed through verb inflection. The current study examined the PADILIH in Thai, a language that does not use verb inflection but instead uses aspectual markers to refer to time. Aims We aimed to evaluate the pattern of impairment of time reference in Thai speakers with agrammatic aphasia, by investigating how grammatical reference to past, present, and future was processed. Methods and Procedures A total of 15 Thai agrammatic speakers and 18 Thai non-brain-damaged (NBD) speakers participated in a sentence production task and an auditory sentence-to-picture matching comprehension task, both of which probed past, present, and future time reference. Outcomes and Results While the NBD participants performed close to ceiling in both production and comprehension, the agrammatic speakers showed significantly more difficulty in conditions requiring reference to the future in both modalities. In production, however, the agrammatic speakers replaced the target future time reference construction with negation (a construction that can be used as an alternative means for future reference). When responses using negation were counted as correct, the individuals with agrammatic aphasia showed equal impairment across conditions. Conclusions The results of this study were inconsistent with the PADILIH predictions: Thai agrammatic speakers experienced more vulnerability in reference to the future than the present and the past. This suggested that impairments of time reference may differ depending on the structure of the language. We hypothesized that the problems with producing future time reference in Thai may be influenced by the grammatical status of the future marker. In addition, the use of negation in place of the target word might have been because this negative construction reduces the processing load for Thai agrammatic speakers.

Several studies have shown selective deficits in the production and comprehension of verb forms referring to the past. On the basis of this evidence the Past Discourse Linking Hypothesis (Bastiaanse et al., 2011) suggests that individuals with aphasia have difficulties with verb forms referring to the past, in comparison to non-past forms such as the present and the future. However, many studies provide counterevidence. This study presents a review of the literature and addresses the question of dissociation between the past and the non-past in aphasia in Greek, a language which distinguishes among three past forms. A mixed group of eight individuals with aphasia and a group of 10 non-brain-damaged speakers performed the two tasks of the Greek version of the Test for Assessing Reference of Time (Bastiaanse, Jonkers, & Thompson, 2008): a sentence completion task (primed by pictures) and a sentence-picture matching task. The sentence completion task tested the present, future and three past tenses: past perfective, past imperfective and present perfect. The sentence-picture matching task tested past perfective, present and future. The production data provide evidence for a deficit in the reference to the past but they also suggest difficulties with the future. Interestingly, a dissociation among the three past tenses tested was found. Above chance performance was found in comprehension across tenses. We consider possible accounts of the data and we discuss the implications of these findings for the Past Discourse Linking Hypothesis.

Recent studies by Bastiaanse and colleagues found that time reference is selectively impaired in people with nonfluent agrammatic aphasia, with reference to the past being more difficult to process than reference to the present or to the future. To account for this dissociation, they formulated the PAst DIscourse LInking Hypothesis (PADILIH), which posits that past reference is more demanding than present/future reference because it involves discourse linking. There is some evidence that this hypothesis can be applied to people with fluent aphasia as well. However, the existing evidence for the PADILIH is contradictory, and most of it has been provided by employing a test that predominantly taps retrieval processes, leaving largely unexplored the underlying ability to encode time reference-related prephonological features. Within a cross-linguistic approach, this study tests the PADILIH by means of a sentence completion task that 'equally' taps encoding and retrieval abilities. This study also investigates if the PADILIH’s scope can be extended to fluent aphasia. Greek- and Italian-speaking individuals with aphasia participated in the study. The Greek group consisted of both individuals with nonfluent agrammatic aphasia and individuals with fluent aphasia, who also presented signs of agrammatism. The Italian group consisted of individuals with agrammatic nonfluent aphasia only. The two Greek subgroups performed similarly. Neither language group of participants with aphasia exhibited a pattern of performance consistent with the predictions of the PADILIH. However, a double dissociation observed within the Greek group suggests a hypothesis that may reconcile the present results with the PADILIH.

This study investigates the characteristics of narrative-speech production and the use of verbs in Turkish agrammatic speakers (n = 10) compared to non-brain-damaged controls (n = 10). To elicit narrative-speech samples, personal interviews and storytelling tasks were conducted. Turkish has a large and regular verb inflection paradigm where verbs are inflected for evidentiality (i.e. direct versus indirect evidence available to the speaker). Particularly, we explored the general characteristics of the speech samples (e.g. utterance length) and the uses of lexical, finite and non-finite verbs and direct and indirect evidentials. The results show that speech rate is slow, verbs per utterance are lower than normal and the verb diversity is reduced in the agrammatic speakers. Verb inflection is relatively intact; however, a trade-off pattern between inflection for direct evidentials and verb diversity is found. The implications of the data are discussed in connection with narrative-speech production studies on other languages.

Background: Individuals with agrammatic aphasia (IWAs) have problems with grammatical decoding of tense inflection. However, these difficulties depend on the time frame that the tense refers to. Verb morphology with reference to the past is more difficult than with reference to the non-past, because a link needs to be made to the past event in discourse, as captured in the PAst Discourse Linking Hypothesis (PADILIH; Bastiaanse, R., Bamyaci, E., Hsu, C., Lee, J., Yarbay Duman, T., Thompson, C. K., 2011. Time reference in agrammatic aphasia: A cross-linguistic study. J. Neurolinguist. 24, 652-673). With respect to reference to the (non-discourse-linked) future, data so far indicate that IWAs experience less difficulties as compared to past time reference (Bastiaanse, R., Bamyaci, E., Hsu, C., Lee, J., Yarbay Duman, T., Thompson, C. K., 2011. Time reference in agrammatic aphasia: A cross-linguistic study. J. Neurolinguist. 24, 652-673), supporting the assumptions of the PADILIH. Previous online studies of time reference in aphasia used methods such as reaction times analysis (e.g., Faroqi-Shah, Y., Dickey, M. W., 2009. On-line processing of tense and temporality in agrammatic aphasia. Brain Lang. 108, 97-111). So far, no such study used eye-tracking, even though this technique can bring additional insights (Burchert, F., Hanne, S., Vasishth, S., 2013. Sentence comprehension disorders in aphasia: the concept of chance performance revisited. Aphasiology 27, 112-125, doi:10.1080/02687038.2012.730603).Aims: This study investigated (1) whether processing of future and past time reference inflection differs between non-brain-damaged individuals (NBDs) and IWAs, and (2) underlying mechanisms of time reference comprehension failure by IWAs.Methods and procedures: A visual-world experiment combining sentence picture matching and eye-tracking was administered to 12 NBDs and 6 IWAs, all native speakers of German. Participants heard German sentences with periphrastic future ('will+V') or periphrastic past ('has+ V-d') verb forms while they were presented with corresponding pictures on a computer screen.Results and discussion: NBDs scored at ceiling and significantly higher than the IWAs. IWAs had below-ceiling performance on the future condition, and both participant groups were faster to respond to the past than to the future condition. These differences are attributed to a pre-existing preference to look at a past picture, which has to be overcome. Eye movement patterns suggest that both groups interpret future time reference similarly, while IWAs show a delay relative to NBDs in interpreting past time reference inflection. The eye tracking results support the PADILIH, because processing reference to the past in discourse syntax requires additional resources and thus, is problematic and delayed for people with aphasia. (C) 2014 Elsevier Ltd. All rights reserved.

Background: Castilian-Spanish, Catalan, Galician, and European Portuguese are the most widely spoken languages of the Ibero-Romance group. An increasing number of authors have addressed the impact of aphasia on the morphosyntax of these varieties. However, accurate linguistic characterisations are scarce and the different sources of data have not been yet compiled.Aims: To stimulate state-of-the-art research, we provided a comprehensive summary of morphosyntactic aspects of Ibero-Romance and a review of how these are affected in non-fluent aphasia. The topics we dealt with are the use of verb argument structure and morphology, sentential negation and word order, definite articles, personal and reflexive pronouns, passives, topicalised constructions, questions, and relative clauses.Methods & Procedures: An exhaustive fieldwork and search of PubMed, Web of Science, and Medline records were performed to retrieve studies focused on morphosyntactic issues concerning the Ibero-Romance varieties. A total of 27 studies produced by 46 authors of varying background emerged. We did not review studies of category-specific deficits and aspects related to bilingual aphasia, although we assume that most speakers of Galician and Catalan are bilingual. Studies of spontaneous speech were included when no controlled experimental tasks were available.Outcomes & Results: The morphosyntactic commonalities of Ibero-Romance have been tackled from different theoretical perspectives. There exist asymmetries in findings which we explain with the use of different tasks (and task complexity) and individual differences between participants.Conclusions: Discourse-linking factors as well as deviations from the canonical pattern are recurrent answers to these asymmetries. A comprehensive theory of impairments in non-fluent aphasia integrating relevant aspects of both structural and processing accounts seems necessary.

The vulnerability of time reference, either marked by means of verbal morphology or by adverbs, has been established in an extensive array of languages in agrammatic aphasia. Recent studies ( Bastiaanse, 2008 , Lee et al., 2008 , Nanousi et al., 2006 , Martinez-Ferreiro, 2010 , Yarbay Duman and Bastiaanse, 2009 ; among others) have determined that far from being general, the observed deficit is sensitive to tense differences with a clear asymmetry between past and non-past forms. To account for these findings, Bastiaanse et al. (2011) formulated the PAst DIscourse LInking Hypothesis (PADILIH), in line with Avrutin's (2000) claim that discourse linking is impaired in Broca's aphasia. Past forms are impaired in opposition to non-past forms due to the fact that the former are discourse linked. However, this hypothesis entails further predictions: if the problem with tense is restricted to discourse linking, we expect present and future forms to be spared or, at least, damaged to the same extent. In this paper, we investigate time reference in Catalan and Spanish using a sentence completion task with pictures and a sentence-to-picture-matching task (adapted from the TART; Bastiaanse et al., 2008 ). The results confirm the predicted deficit: forms referring to the past are more impaired than forms referring to non-past, that is, tenses referring to the present and future were better preserved. However, in comprehension, asymmetries arise between present and future forms. Implications for the PADILIH are discussed.

Background: Several studies on time reference show that monolingual agrammatic speakers have difficulty producing and/or comprehending verb forms referring to past events or actions. The PAst Discourse LInking Hypothesis (PADILIH) has been formulated to account for this phenomenon (Bastiaanse et al., 2011). In the current study on bilingual aphasia we examine whether time reference problems, especially reference to the past, extend to both languages of bilinguals with agrammatic aphasia. The two languages, Swahili and English, have different verb morphology for expressing reference of time. Aims: The current study tested the production and comprehension of reference of time through verb morphology in two languages of SwahiliEnglish bilingual agrammatic speakers. Methods & Procedures: A total of 13 agrammatic speakers and 13 non-brain-damaged individuals were tested using an adaptation of the Test for Assessing Reference of Time (TART; Bastiaanse, Jonkers, & Thompson, 2008; Swahili version: Abuom & Bastiaanse, 2010). Reference to the past, present, and future conditions were examined through a sentence-completion and a picturesentence-matching task. Outcomes & Results: While the non-brain-damaged participants performed at ceiling in both languages, the agrammatic individuals' performance showed a selective deficit of reference to the past on both comprehension and production tasks. A similar pattern was observed in the two languages in spite of the structural differences. Conclusions: The PAst Discourse LInking Hypothesis (PADILIH) was supported by these results. Furthermore it has been revealed that time reference deficits extend to both tested languages of bilingual speakers with agrammatic aphasia regardless of the structure of languages mastered pre-morbidly. The implications of these findings for the theories of bilingual agrammatism are discussed.

Most studies on spontaneous speech of individuals with agrammatism have focused almost exclusively on monolingual individuals. There is hardly any previous research on bilinguals, especially of structurally different languages; and none on characterization of agrammatism in Swahili. The current study identifies the features of Swahili agrammatic narrative and spontaneous speech, and compares the use of verb inflections for tense and time reference in English and Swahili in six bilingual agrammatic speakers and 12 non-brain-damaged speakers matched on age, native language and education level to the agrammatic speakers. The results show a remarkable similarity between the agrammatic phenomena in both languages on the typical agrammatic features: utterance length and speech rate are reduced and the proportion of grammatical sentences and complex sentences is lower than normal. Analysis of verb inflection demonstrates that there are no qualitative differences between the Swahili and English samples: in both languages reference to the past is more impaired than reference to the present. However, the use of verb inflection in general is better preserved in Swahili than English. English verb inflections are frequently omitted, whereas Swahili verb inflections are substituted.The implications of these findings for theories on agrammatism are discussed. (C) 2012 Elsevier Ltd. All rights reserved.

Objectives Individuals with nonfluent agrammatic aphasia show impaired production and comprehension of time reference via verbal morphology. However, cross-linguistic findings to date suggest inconsistent evidence as to whether tense processing in general is impaired or time reference to the past is selectively difficult in this population. This study examined production and comprehension of time reference via verb morphology in Korean-speaking individuals with nonfluent aphasia. Methods A group of 9 healthy controls and 8 individuals with nonfluent aphasia (5 for the production task) participated in the study. Sentence priming production and auditory sentence to picture matching tasks were used, parallel with the previous cross-linguistic experiments in English, Chinese, Turkish, and others. Results The participants with nonfluent aphasia showed different patterns of impairment in production and comprehension. In production, they were impaired in all time references with errors being dominated by substitution of incorrect time references and other morpho-phonologically well-formed errors, indicating a largely intact morphological affixation process. In comprehension, they showed selective impairment of the past, consistent with the cross-linguistic evidence from English, Chinese, Turkish, and others. Conclusion The findings suggest that interpretation of past time reference poses particular difficulty in nonfluent aphasia irrespective of typological characteristics of languages; however, in production, language-specific morpho-semantic functions of verbal morphology may play a significant role in selective breakdowns of time reference.

WOS: 000341676600010, This study presents the pioneering data on the neurological representation of grammatically marked evidentials with regard to their dissolution in agrammatic Broca's aphasia. Across two tasks, we investigated the production of finite verb inflections for evidential categories and identification of the information sources these evidential categories are mapped on in Turkish individuals with agrammatic aphasia. In Turkish, information source is grammatically marked for three different past contexts: direct perception, reportative, and inferential. The following research questions were explored: (1) is inflection for different evidential categories equally affected in Turkish agrammatic aphasia? (2) Is identifying the categories of information source impaired? Turkish agrammatic speakers and non-brain-damaged speakers (NBDs) were tested with a production and a source identification tasks. Our findings demonstrate that in Turkish agrammatic speakers the direct perception evidential was more affected in production than the inferential and reportative evidentials. However, the agrammatic speakers retained the ability to identify the source for the direct perception. We argue that information source values conveyed by evidential forms are impaired in agrammatic aphasia. These findings are discussed on the basis of earlier studies to time reference and tense in agrammatism

Background: Agrammatic speakers have problems with grammatical encoding and decoding. However, not all syntactic processes are equally problematic: present time reference, who questions, and reflexives can be processed by narrow syntax alone and are relatively spared compared to past time reference, which questions, and personal pronouns, respectively. The latter need additional access to discourse and information structures to link to their referent outside the clause (Avrutin, 2006). Linguistic processing that requires discourse-linking is difficult for agrammatic individuals: verb morphology with reference to the past is more difficult than with reference to the present (Bastiaanse et al., 2011). The same holds for which questions compared to who questions and for pronouns compared to reflexives (Avrutin, 2006). These results have been reported independently for different populations in different languages. The current study, for the first time, tested all conditions within the same population.Aims: We had two aims with the current study. First, we wanted to investigate whether discourse-linking is the common denominator of the deficits in time reference, wh questions, and object pronouns. Second, we aimed to compare the comprehension of discourse-linked elements in people with agrammatic and fluent aphasia.Methods and procedures: Three sentence-picture-matching tasks were administered to 10 agrammatic, 10 fluent aphasic, and 10 non-brain-damaged Russian speakers (NBDs): (1) the Test for Assessing Reference of Time (TART) for present imperfective (reference to present) and past perfective (reference to past), (2) the Wh Extraction Assessment Tool (WHEAT) for which and who subject questions, and (3) the Reflexive-Pronoun Test (RePro) for reflexive and pronominal reference.Outcomes and results: NBDs scored at ceiling and significantly higher than the aphasic participants. We found an overall effect of discourse-linking in the TART and WHEAT for the agrammatic speakers, and in all three tests for the fluent speakers. Scores on the RePro were at ceiling.Conclusions: The results are in line with the prediction that problems that individuals with agrammatic and fluent aphasia experience when comprehending sentences that contain verbs with past time reference, which question words and pronouns are caused by the fact that these elements involve discourse linking. The effect is not specific to agrammatism, although it may result from different underlying disorders in agrammatic and fluent aphasia. (C) 2014 Elsevier Ltd. All rights reserved.

Background: Morphological errors of tense and agreement are salient in agrammatic aphasia. The PADILIH predicts impairments in discourse linking that translate to greater difficulties in referring to a past event time than to a future or a present event time. In Catalan, the Periphrastic conditional tense (e.g., if the man had had time, he would have...) refers to the past and the Simple conditional tense refers to the future (e.g., if the man had time, he would...). These two tenses refer to an event that may happen (irrealis).Aims: We fill in the gap of the conditional tense and provide further data to study contrasts in verb inflection for time reference. We predict that verb forms that refer to an irrealis past event (Periphrastic conditional) are more impaired than forms that refer to an irrealis future event (Simple conditional and Future). We also predict that there are no differences between verb forms that refer to an irrealis future event (Simple conditional and Future). We also assessed whether problems in time reference extend to individuals with non-fluent aphasia that are not typical agrammatic Broca aphasia.Methods & Procedures: A sentence completion task that included 60 sentences (20 per type) of equal length in a Conditional structure (if-sentences) was designed. We tested three sentence types: Periphrastic conditional, Simple conditional and Future. The task was administered to nine participants with non-fluent aphasia and nine age-matched non-brain-damaged participants.Outcomes & Results: The Control group scored at ceiling on the three sentence types. Participants with non-fluent aphasia were most impaired in the production of the Periphrastic conditional as compared with the Simple conditional and the Future.Conclusions: When irrealis event times are compared, past events are more impaired than future events. These results can be explained by a deficit in time reference as predicted by the PADILIH. Our data reveal that the predictions of the PADILIH also hold for non-fluent speakers who have been diagnosed with Transcortical motor aphasia.

Background: Reference to an event's time frame can be accomplished through verb inflection. In agrammatic aphasia, a deficit in past time reference has been identified by Bastiaanse and colleagues (2011). In fluent aphasia, specific problems with this time frame (expressed by the past tense) have been found as well (Dragoy & Bastiaanse, 2013; Jonkers & de Bruin, 2009). However, time reference does not always coincide with tense; in languages such as Dutch and English, reference to the past can be established by using past tense (e.g., "he wrote a letter") or a present tense auxiliary in combination with a participle, i.e., the present perfect (e.g., "he has written a letter").Aims: The goal of this study is twofold. First, it aims to untangle tense problems from problems with past time reference through verb morphology in people with aphasia. Second, this study aims to compare the production of time reference inflection by people with agrammatic and fluent aphasia.Methods & Procedures: A sentence completion task was used to elicit reference to the non-past and past in Dutch. Reference to the past was tested through (1) a simple verb in past tense and (2) a verb complex with an auxiliary in present tense + participle (the present perfect). Reference to the non-past was tested through a simple verb in present tense. Fourteen agrammatic aphasic speakers, sixteen fluent aphasic speakers, and twenty non-brain-damaged speakers (NBDs) took part in this study. Data were analysed quantitatively and qualitatively.Outcomes & Results: NBDs scored at ceiling and significantly higher than the aphasic participants. Agrammatic speakers performed worse than fluent speakers, but the pattern of performance in both aphasic groups was similar. Reference to the past through past tense and [present tense auxiliary + participle] was more impaired than reference to the non-past. An error analysis revealed differences between the two groups.Conclusions: People with agrammatic and fluent aphasia experience problems with expressing reference to the past through verb inflection. This past time reference deficit is irrespective of the tense employed. The error patterns between the two groups reveal different underlying problems.

Background: It has been argued that agrammatic speakers' production of sentences in derived order is impaired (The Derived Order Problem Hypothesis, DOP-H), and that the underlying deficit in bilingual individuals with agrammatic Broca's aphasia may cause different surface manifestations in the languages when they differ in terms of their grammatical morphology. The current study presents results of a study on sentence production in Swahili-English bilingual agrammatic speakers. The two languages, Swahili and English, differ significantly in terms of their verbal morphology. Aims: The current study tested the production of sentences in base and derived orders of arguments in the two languages of Swahili-English bilingual agrammatic speakers. Methods & Procedures: Eight agrammatic and eight non-brain damaged individuals participated in the study. A sentence elicitation test was used to examine the production of sentences in base and derived word orders in Swahili and English. The base order condition consisted of active and subject-cleft sentences, whereas the derived order condition tested passive and object-cleft sentences. Outcomes & Results: The non-brain-damaged individuals performed at ceiling in both languages. The agrammatic speakers' results, however, show sentences in derived order condition and were more difficult to produce than those in base order, similarly across the two languages irrespective of their morphological differences. Moreover, the embedded sentences were also more difficult to produce than simple sentences for agrammatic speakers. Conclusions: The current data partially support the DOP-H and provide new insight into sentence production deficit of bilingual individuals with agrammatic Broca's aphasia. The findings are discussed with respect to the theories of sentence production in agrammatic speakers.

Cross-linguistic data suggest that the grammatical categories of tense and aspect are not generally impaired in individuals with aphasia (see Bastiaanse et al., 2011 for a review). Rather, and more specifically, verb forms expressing reference to the past or conveying perfective semantics are more impaired than verb forms expressing reference to the non-past (present or future) or conveying imperfective semantics, both in comprehension and production. The present study used some structural properties of Russian to systematically test the interaction of time reference and aspect in non-fluent and fluent aphasia.The Test for Assessment of Reference of Time (TART; Bastiaanse, Jonkers, & Thompson, 2008; Russian version Dragoy & Bastiaanse, 2010) was used to elicit production of four verb forms in sentence context: past perfective, non-past perfective, past imperfective and non-past imperfective. The results showed that non-past time reference had a general advantage over past time reference, all aspectual forms being collapsed. However, an interaction between time reference and aspect was found: imperfective verbs were better produced in the non-past, whereas production of perfective verbs was better preserved in the past time frame. Non-fluent and fluent aphasic speakers showed largely overlapping performance.These results demonstrated that the advantage of a particular time reference depends on aspectual characteristics of the verb. The performance of both non-fluent and fluent aphasic speakers can be explained in terms of prototypical and non-prototypical matches of time reference and aspectual semantics: perfectives primarily refer to completed, past events while imperfectives prototypically describe ongoing, non-past events. (C) 2012 Elsevier Ltd. All rights reserved.

Background: Broca's aphasic or agrammatic participants are assumed to have problems with the inflection of moved verbs. Recently, Bastiaanse (2008) has shown that verb inflection in base position is also difficult for these participants, especially if reference to the past is involved. However, Bastiaanse only examined the data of Broca's aphasic participants and restricted herself to verb production. In the current study we will examine the existence of a more central deficit in tense marking in production and comprehension in aphasic participants. Aims: The production and comprehension of tensed verbs will be studied in a group of Broca's aphasic participants. The data of a group of participants suffering from Wernicke's aphasia will be used for comparison. Methods Procedures: Seven participants with Broca's aphasia and five with Wernicke's aphasia performed a sentence-to-picture matching task for comprehension and a sentence completion task for production with present or past tense as the crucial conditions. Both tests contained 40 items. Results on the tests were analysed quantitatively and qualitatively. Outcomes Results: Although production was more impaired than comprehension in Broca's aphasic participants, past tense was more difficult to interpret than present tense, especially for those participants who showed comprehension problems. Problems with the interpretation of tense were also found in the group of Wernicke's aphasic participants. Furthermore, for these participants past tense forms were also more difficult to produce than present tense forms. Conclusions: The results suggest that past tense in general is difficult to process for aphasic participants. We relate this finding to the semantic notion of past tense.

The present study aims to contribute to the ongoing discussion about the impact of discourse-linking deficits on the performance of individuals with aphasia by providing new data from a set of rarely investigated constructions: sentences in which a clitic pronoun coexists alongside with the full DP it agrees with. To do so, we use data of individuals with non-fluent aphasias who need to overcome the difficulties in direct object (accusative) clitic production. This results in overproduction of non-target clitic right dislocations (RDs) and clitic doubling (CD). Data from 15 individual's native speakers of Spanish and Catalan are discussed. Data complement the results of previous investigations on discourse-linking effects in these languages, allowing the interpretation of results across constructions.

Many studies have shown that verb inflections are difficult to produce for agrammatic aphasic speakers: they are frequently omitted and substituted. The present article gives an overview of our search to understanding why this is the case. The hypothesis is that grammatical morphology referring to the past is selectively impaired in agrammatic aphasia. That is, verb inflections for past tense and perfect aspect are hard to produce. Furthermore, verb clusters that refer to the past will be affected as well, even if the auxiliary is in present tense, as in he has been writing a letter. It will be argued that all these verb forms referring to the past require discourse linking [Zagona, K. (2003). Tense and anaphora: Is there a tense-specific theory of coreference. In A. Barrs (Ed.), Anaphora: A reference guide (pp. 140-171). Oxford: Blackwell Publishing] and discourse linking is affected in agrammatic aphasia [Avrutin, S. (2006). Weak syntax. In K. Amunts, & Y. Grodzinsky (Eds.), Broca's region (pp. 49-62). New York: Oxford Press]. This hypothesis has been coined the PAst DIscourse LInking Hypothesis (PADILIH) [Bastiaanse, R., Bamyaci, E., Hsu, C.-J., Lee, J., Yarbay Duman, T., & Thompson, C. K. (2011). Time reference in agrammatic aphasia: A cross-linguistic study. Journal of Neurolinguistics, 24, 652-673]. The PADILIH has been tested in several languages and populations that have hardly been studied before in aphasiology: languages such as Turkish, Swahili and Indonesian were included, as well as monolingual and bilingual populations. In all these populations, the same test has been used: the Test for Assessing Reference of Time [Bastiaanse, R., Jonkers, R., & Thompson, C. K. (2008). Test for assessing reference of time (TART). Groningen: University of Groningen] to enable reliable comparisons between the languages. The results show that the PADILIH predicts the performance of agrammatic speakers very well: discourse-linked grammatical morphemes expressing time reference to the past are hard to produce for agrammatic speakers, whereas non-discourse-linked verb inflections (for present and future) are relatively spared. In languages that use aspectual adverbs (free-standing and optional time reference markers), such as Chinese and Indonesian, time reference to all time frames is impaired, since all aspectual adverbs, regardless of the time frame they refer to, require discourse linking. Remarkably, the problems are not restricted to grammatical morphemes: the production of temporal lexical adverbs is impaired as well.