Comparing languages -- A history of crosslinguistic research on language acquisition -- The comparative method of language acquisition research -- The structure of Mayan languages -- The acquisition of the Mayan lexicon -- The acquisition of the Mayan intransitive verb complex -- The acquisition of the Mayan transitive verb complex -- The acquisition of person marking in the Mayan verb complex -- The acquisition of Mayan argument structures -- Argument realization in Mayan languages -- Conclusion.