Recent work in syntactic theory has revealed that word order is more constrained in subordinate clauses, particularly nonasserted clauses, than in main clauses (Ross, 1973; Hooper & Thompson, 1973). On the other hand, main clauses are restricted in the extent to which they allow pronominalization and verb phrase deletion (Lakoff, 1968). These formal properties of language may be due to a strategy the listener uses during sentence comprehension: interpret the asserted (main) clause as soon as possible. Two psycholinguistic studies which support the use of this comprehension strategy are reported. The first indicates that adult listeners have better access to the meaning of main clauses during sentence comprehension. The second study examines developmental changes in the listener's access to the nonsemantic, verbatim form of the clauses of temporal and coordinate sentences. The results indicate a general tendency across ages to interpret main clauses more quickly than subordinate clauses, with a shift at the four-year level to interpret initial clauses, regardless of structural type, more quickly than final clauses. The two studies together are consistent with the hypothesis that differences in the form of main and subordinate clauses are a product of comprehension strategies throughout development. (Author)