時態(tài)

　　1.時間狀語從句，條件句中，從句用一般現(xiàn)在時代替將來時

　　When, while, before, after, till, once, as soon as, so long as, by the time, if, in case (that), unless, even if, whether, the moment, the minute, the day, the year, immediately

　　典型例題

　　(1)He said he________me a present unless I_______ in doing the experiment.

　　A. had not given; had not succeeded　　B. would not give; succeed

　　C. will not give; succeed　　　　　　 D. would not give; will succeed.

　　答案B. 在時間，條件或讓步主語從句中一般不用將來時。本題有He said，故為過去式。主句用將來時，故選B. 此處用一般過去式代替了過去將來時。

　　2.表示 "意圖"、"打算"、"安排"、常用于人。

　　常用詞為 come, go, start, arrive, leave, stay等。

　　I'm leaving tomorrow.

　　Are you staying here till next week?