An attempt to show that a complex interaction of syntactic forms with semantic and pragmatic functions has to be taken into account in order to formulate the conditions under which certain syntactic constructions, which are usually thought to be restricted to main clauses, can occur in subordinate clauses as well. (An example of such a construction is negative adverb preposing as in 'Never before have prices been so high', 'Nixon regrets that never before have prices been so high', and 'I knew that never before had prices been so high'). Basically, the use of such constructions in subordinate clauses is said to be related to a speaker's desire to be understood as committed to the truth of the subordinate clause.