Old and Middle Japanese are the pre-modern periods of the attested history of the Japanese language. Old Japanese (OJ) is largely the language of the 8th century, with a modest, but still significant number of written sources, most of which is poetry. Middle Japanese is divided into two distinct periods, Early Middle Japanese (EMJ, 800–1200) and Late Middle Japanese (LMJ, 1200–1600). EMJ saw most of the significant sound changes that took place in the language, as well as profound influence from Chinese, whereas most grammatical changes took place between the end of EMJ and the end of LMJ. By the end of LMJ, the Japanese language had reached a form that is not significantly different from present-day Japanese. OJ phonology was simple, both in terms of phoneme inventory and syllable structure, with a total of only 88 different syllables. In EMJ, the language became quantity sensitive, with the introduction of a long versus short syllables. OJ and EMJ had obligatory verb inflection for a number of modal and syntactic categories (including an important distinction between a conclusive and an (ad)nominalizing form), whereas the expression of aspect and tense was optional. Through late EMJ and LMJ this system changed completely to one without nominalizing inflection, but obligatory inflection for tense. The morphological pronominal system of OJ was lost in EMJ, which developed a range of lexical and lexically based terms of speaker and hearer reference. OJ had a two-way (speaker–nonspeaker) demonstrative system, which in EMJ was replaced by a three-way (proximal–mesial–distal) system. OJ had a system of differential object marking, based on specificity, as well as a word order rule that placed accusative marked objects before most subjects; both of these features were lost in EMJ. OJ and EMJ had genitive subject marking in subordinate clauses and in focused, interrogative and exclamative main clauses, but no case marking of subjects in declarative, optative, or imperative main clauses and no nominative marker. Through LMJ genitive subject marking was gradually circumscribed and a nominative case particle was acquired which could mark subjects in all types of clauses. OJ had a well-developed system of complex predicates, in which two verbs jointly formed the predicate of a single clause, which is the source of the LMJ and NJ (Modern Japanese) verb–verb compound complex predicates. OJ and EMJ also had mono-clausal focus constructions that functionally were similar to clefts in English; these constructions were lost in LMJ.