引导时间状语从句的常用连词有when(当……时),before(在……之前),after(在……之后),while(在……期间),since(自……以来),as(当……时,一边……一边),till/until(直到),as soon as(一……就)等,但有一些词形式上不是连词,而实际用法上却具有连词功能,可以用来引导时间状语从句。常见的这类似非而是的特殊连词主要有以下三类。 The common conjunctions of adverbial clauses of the lead time are when (when...), before (before...), after (after...), while (after...), since (since...), as ( When..., while...), till/until, as soon as, etc., but there are some words that are formally not conjunctives, but in practice they have a conjunction function that can be used to Lead time adverbial clause. The common special non-relationships are mainly the following three categories.