A study investigating the acquisition of empty categories (ECs) in Sinhala, a language of the Indo-Aryan family spoken in Sri Lanka, is reported in part. The results examined here concern ECs occurring in a subset of adverbial clause types differing with regard to the kinds of null subjects they permit, including those obligatorily coindexed, i.e., "control structures." Subjects for collection of production data were 74 children acquiring Sinhala as a first language, aged 2.0 to 4.0 years. Data were drawn from utterances with various forms of one clause structure. Subjects in a test of comprehension were 169 native Sinhalese speakers aged 2 to 6 years who participated in a standardized "act-out" sentence comprehension task. The sentences involved two clause constructions. Results suggest a continuous"structure-dependence" in children's early hypotheses about the prolific ECs in Sinhala, including those involved in control structures. The fact that the children distinguished the interpretation of ECs in the full set of adverbial forms tested reflects sensitivity to the abstract structure of the forms. These findings appear consistent with a generalized control theory. (MSE)