Research supported in part by a grant from the United States Public Health Service. (DD)

Dialogues of sets of socially similar twins are studied. The opinion that twins have slower syntactic development than non-twins is seriously questioned. Dialogues with twins saying the same utterance together, correcting each other, quarreling, playing verbal games, etc. are analyzed in their deep structure. (SCC)

The linguistic structure of specific introductory type clauses, which appear at a relatively high frequency in the utterances of a severely brain damaged fluent aphasic with neologistic jargon speech, is examined. The analysis is restricted to one fifty-six-year-old male patient who suffered massive subdural hematoma. (SCC)

The difficulty of understanding embedded sentences is discussed in relation to Bever's hypothesis: if a sentence segment has a double function by means of the same processing strategy it is difficult to interpret the sentence. An alternative to this theory is proposed due to the author's experiments. (SCC)

Various theories are presented in support of a rationist approach to linguistics. (Author/HP)

This paper attempts to demonstrate that: (a) syntax is dependent on factors of cognitive and non-cognitive meaning; and (b) criteria for linguistic competence can only be fully met when full command of cognitive and non-cognitive meaning is present. Results have implications for future models of language and language acquisition. (CHK)