ABSTRACTSix tests of the spontaneous speech of twenty-one English-speaking children (1 ; 10 to 2 ; 8; MLUs 1.53 to 4.38) demonstrate the presence of the syntactic category determiner from the start of combinatorial speech, supporting nativist accounts. Children use multiple determiners before a noun to the same extent as their mothers (1) when only a and the or (2) all determiners are analyzed, or (3) when children and mothers are matched on determiner and noun types and determiner+noun tokens. (4) Overlap increases as opportunity for overlap increases: children use multiple determiners with more than 50% of nouns used at least twice with a determiner and with 80% of nouns used at least six times with a determiner. (5) Formulae play a limited role in low-MLU children's determiner usage, increasing with MLU. (6) Less than 1% of determiner uses are errors. Prior results showing no overlap are likely a sampling artifact.