I ought to write to him today／tomorrow．

我今天／明天应该给他写封信。

I knew I ought to write to him．

我那时知道我应该给他写封信。

She said I ought to write．

她说我应该写。

I know／knew that I ought to have written．

我知道／那时知道我该写的。

ought与带to的不定式连用。为了提醒学生这一点，常称之为ought to。

问句或话语中用ought to的时候，可以用 should来回答；用should的问句或话语也可以用ought to回答：

-You ought to put in central heating．

-Yes，I suppose I should．

-你应该装上暖气。

-是的，我应该装。

1. 2. Ask Ss to read the text again and pay attention to the modal verbs and then finish Ex1,2,3.

Step 5. Homework

1. Ask Ss to review what has been learned in this period.

2. Ask Ss to act out the dialogue of Ex2 of Discovering Useful Structures on P13.