時態一致

1)并列謂語的時態一致。
　　【例如】Yesterday I went shopping, bought some books and had dinner at a good restaurant.
　　The soldier looked at him, exchanged glances with his comrade and took out the gun.
　　2)主從復合句的時態一致。
　　a)主句為現在時、將來時、現在完成時，賓語從句謂語動詞時態按情況而定。
　　【例如】
　　I wonder what will happen tomorrow.
　　I wonder what happened to him yesterday.
　　I wonder what is happening now outside.
　　b)主句為過去時態，賓語從句一般用過去時態。如果賓語從句說明的是客觀真理，用一般現在時。
　　【例如】
　　He told me he made a big mistake.
　　He told me he would go to Beijing the next day.
　　He told he had finished his task.
　　The teacher told students that the earth moves around the sun.(客觀真理)
　　3)定語從句和比較狀語從句時態不受主句影響。
　　【例如】
　　The universityswhereshe is studying was founded in 1950.
　　You now speak English better than you spoke it last year.
　　4)時間和條件狀語從句中，常用現在時表示將來。
　　【例如】
　　We will cancel our trip if it rains tomorrow.
　　I will go to visit the Summer Palace as soon as I arrive in Beijing.