<例句>
She said she understood.
她说她懂了。
<语法分析>
当主句和从句的谓语动词所表示的动作同时发生时，从句需要用一般过去时或过去进行时，即要注意句子时态的呼应。当从句所表示的内容是个普遍真理或一般规律时或当从句有绝对表示过去的时间状语时，句子的主句和从句不存在时态上的呼应。联系动词be的一般时可表示完成概念，现在完成时，可表示“到说话时为止”。
<触类旁通>
(1) I wasn't sure whether you (were) [be] watching TV or not.
我不敢肯定你是不是在看电视。
语法分析：主句和从句的谓语动词所表示的动作同时发生时，从句需要用一般过去时或过去进行时。
(2) She told me she had graduated from university three years before.
她告诉我她三年前就大学毕业了。
语法分析：从句谓语动词所表示的动作发生在主句谓语动词所表示的动作之前时，从句多用过去完成时。
(3) He said he would do anything for his own home.
他说他愿为他自己的家庭做任何事情。
语法分析：从句谓语动词所表示的动作发生在主句谓语动词所表示的动作之后时，从句多用过去将来时。
(4) My teacher said that light travels much faster than sound.
我的老师说光的速度比声音的速度快得多。
语法分析：从句所表示的内容是个普遍真理或一般规律时，不存在时态的呼应。
(5) My fever is gone.
我的烧已经退了。
语法分析：联系动词be的一般时可表示完成概念。
<巩固练习>
(1) The facts proved that the earth and all the other panets _____[move] around the sun.
(2) The teacher said that when a person _____[learn] a foreign language, he must not translate everything into his own.
(3) She said that the little boy ______[break] his leg.
(4) I was told that my brother ______[go] home tomorrow.
(5) He told me that he ______[be] only 14.
(6) You will notice that this word _____[has] several meanings.
(7) I wonder who _____[build] the great bridge.
(8) It ______[be] since his death.
(9) Ever since then, the monkey _____[come] out only at night.
(10) He told me yesterday that she _____[murder] three days before.
<参考答案>
(1) move (2) is learning (3) had broken (4) is going (5) is (6) has (7) built (8) is (9)comes (10) had been murdered
