TENSE CHOICE IN ADVERBIAL WHEN CLAUSES

This article presents an analysis of the temporal structure expressed by when and examines the possibilities of tense choice in adverbial wh en clauses and in the superordinate clauses supporting them. It argues that when is a free relative adverb rather than a conjunction, and th at it establishes a ''common frame'' that includes both a time of orie ntation from the tense structure of the superordinate clause and a tim e of orientation from the tense structure of the when clause. This tem poral structure represents the semantics of when, which is therefore i nterpreted as 'at a/the time at which'. The author goes on to argue th at the unmarked use of tenses is that in which one of nine possible te mporal configurations involving the common frame expressed by when is realized. Apart from these unmarked options, there are also some marke d uses of relative tenses, viz. tenses effecting ''indirect binding'' or expressing irrealis. Finally, there are some possibilities of the w hen clause using an absolute tense form. Since all these cases represe nt a marked tense choice, they are relatively uncommon and subject to severe restrictions.