T: Good. Now let's check the answers.

Then ask three students to read the three paragraphs, and check the answers together.

T: Well done! Let's learn something further. Who can tell me the main verbs?

S: Verbs filled in blank one, two, three, five, eight, nine, ten are main verbs.

T: You are right. How about the others?

S: They are infinitives.

T: Yes. Infinitives are commonly used. Today, we will learn infinitive systematically.

Step II Grammar

T: The infinitive is the base form of a verb. It may be preceded by "to" (the to-infinitive) or stand alone (the base or zero infinitive). Just as I said just now, it is a kind of non-finite. As we can infer from the name, it can't be used as the main verb in a sentence. But it has different tenses and voices. I will show different forms of the infinitive on the screen.

Show the following chart on the screen, and explain it.

The perfect infinitive to have done He is believed to have saved the drowning boy. The continuous infinitive to be doing I happened to be waiting for the bus when the accident happened. The perfect continuous infinitive to have been doing He pretended to have been painting all day. The passive infinitive to be done I am expecting to be given a pay-rise next month. T: Try to remember this chart. Next, let's learn the functions of it. First it can be used as subject and predicative. All of you are familiar with this proverb "眼见为实". Who can tell me the English version for it?

S: To see is to believe.

T: That's right. In this proverb, the infinitive to see is used as the subject, while to believe is used as the predicative. Clear? ... Can you give me other examples?

S: To be or not to be, that's the question.