A study of a child's earliest pretransformational language acquisition processes. A model is constructed based on the assumptions (1) that syntactic acquisition occurs through the testing of hypotheses reflecting the initial structure of the acquisition mechanism and the language data to which the child is exposed; (2) that semantics confirms or disconfirms grammatical hypotheses and is part of the initial structure available to the child. The model produces partial or complete analyses, since the child responds differentially to sentences according to the degree to which he understands them. The acquisition process is defined in three stages: (1) words are recognized as concrete referents; (2) syntactic development begins, separating action classes from thing classes and introducing modifiers; (3) hierarchical order appears and sentence subjects begin to be recognized. Although word comprehension is influenced by contiguous words, the child's ability to associate is not limited to physically associated words.