初四年级中考一轮复习语法专项（4）十一、状语从句（一）时间状语从句：由when, while, before, after, since, as soon as, till / until引导的从句1）when与whileeg.1)Ill tell her the good news _he comes back. 2)Aunt Wang came in while we were watching TV3)since:自从以来(since从句常用一般过去时)注意主句通常用现在完成时，但当主句表示一种状态，用一般现在时eg.1)He has lived there since he came to China 2)It is two years since her mother died.（二）条件状语从句：由if (如果)引导的从句eg.I will go to the park if it _ (not rain) tomorrow.注意：条件状语从句与以下句型的转换1）祈使句，an
