PhD (Afrikaans en Nederlands), North-West University, Vanderbijlpark Campus, 2019 Modality is a challenging and complex field in linguistics and together with tempus and aspect is probably one of the most dynamic and important terrains in current research. Many difficulties confront the researcher in the field of modality as various disputes surround the definition and typological categorization of terms in a field without dominant theories or research methods. In the study of Afrikaans a gap exists regarding modality, specifically on modal auxiliary verbs. During the last forty years only Conradie (2016, 2018a, 2018b) contributed to research on modal auxiliary verbs in Afrikaans. No other contemporary research covers the work done in this thesis. Earlier research is dated and only De Villiers (1971), Ponelis (1979), Van Schoor (1983), and Conradie (1976, 1979, 1980, 1987, and 1992) could be interrogated for information on the meaning and syntactical functions of modal auxiliary verbs and the changes in these verbs during the past century. The lacunae in knowledge are caused by insufficient historical data and a lack of sound theoretical approaches as the existing research tends to rely on anecdotal evidence and instinctive responses. William Croft’s Radical Construction Grammar (2001) forms the point of departure for this investigation of modality. RCG asserts that both form (syntax) and function (semantics) are important and therefore the meaning of modal auxiliary verbs cannot be investigated without keeping syntax and context in mind. This thesis is the first attempt to approach modality in Afrikaans from a construction grammar perspective, but indeed is one of only few attempts to do so in the broader field of linguistics. The thesis also focusses on some of the disputes relating to modality and proposes a working model formed by a synthesis of current and traditional theories to supplement RCG when semantic maps and constructions are used to investigate and describe meaning. This working model is used to probe the central modal auxiliary verbs in Afrikaans. Methods gleaned from corpus linguistics (Biber et al., 1998) are also used and a historical corpus existing of four periods spanning 100 years with 20 year gaps is introduced. The use of modal auxiliary verbs is annotated and classified according to specific micro parameters. Every modal auxiliary verb is discussed in a separate chapter by making use of the new working model aided by statistical methods from corpus linguistics.The working model enabled the researcher to indicate the prototypical as well as peripheral meanings of each modal auxiliary verb. As Construction Grammar doesn’t focus exclusively on semantics but emphasises the context in which words are used, the possible uses of each modal is exposed and investigated. One of the salient findings is the constructionalising of moenie (mustn’t) to the status of a central modal auxiliary verb. This study departed with research on nine core modal auxiliary verbs, but ended with ten. Also, the frequency of kan has increased drastically during the past hundred years so that it has become by far the most frequently used modal auxiliary verb in Afrikaans. Kan (can) is shown to be a dynamic and competitive modal and in the epistemic and the deontic meaning domains the use of kan overlaps with mag (may) and has ushered out and taken over some of the meanings of mag. Findings involving moet (must) are also noteworthy as this modal has undergone a change in emphasis. During the second period (1940’s-1950’s), a period that overlaps with the rise of Afrikaner Nationalism and Apartheid, the use of moet (must) increased significantly but then frequency of use as well as the intensity and power of moet declined again. Currently the use of moet is less dominant while its tone levelled out as well. The thesis provides a comprehensive semantic data base of the synchronic state of ten central modal auxiliary verbs in Afrikaans, namely moet, moes, mag, kan, kon, wil, wou, sal, sou and the latest addition to this group, moenie. (Literally translated: must, should, may, can, could, will, would, shall, would and “must not”.) In addition the most important changes in the use of these verbs over a hundred years were pointed out. Afrikaans is compared to the two other closely related Germanic languages, English and Dutch, in order to contribute to the wider discussion of modality in Germanic languages. This comprehensive data base with its synchronic information, as well as observations regarding various diachronic changes fills an important gap in the knowledge regarding Afrikaans auxiliary verbs. Doctoral