The first stage of combinatorial speech is better described as variable than uniform. Talk of variants obscures two different aspects of language (knowledge and use) and two different aspects of language development -- acquisition of the grammar (competence) and deployment of the grammar in speaking and listening (performance). Null subjects and…

Ticuna (ISO: tca) is a language isolate spoken in the northwestern Amazon Basin (Brazil, Colombia, Peru). Ticuna has more speakers than almost all other Indigenous Amazonian languages and -- unlike most languages of the area -- is still learned by children. Yet academic linguists have given it relatively little research attention. Therefore, to…