新编英语教程第三版第二册unit3

Unit 3

I Lead-in

II Language Structures

Modal auxiliaries

1. would + perfect infinitive used to express “unfulfilled wish”

. I would have liked to sign up, but I sprained my ankle.

2. should /ought to + perfect infinitive used to express “unfulfilled ob ligation”

needn’t + perfect infinitive expressing “unnecessary past actions”. 1) She should/ ought to have had more oral practice during the term.

2) She needn’t have learned all the dialogues by heart.

3. may /might + perfect infinitive used to expre ss “speculations about past

actions”

can /could not + perfect infinitive used to express “negative deduction about past

actions”

. 1)He may/might have gone to the library.

2) She can’t/couldn’t have gone to the library.

4. must + perfect infinitive used to express “affirmative deduction about past actions”

may /might as well used with the second person pronoun expressing “suggestions”

. 1) She must have gone to the language lab.

2) You may/might as well use my bike.

Preparatory Questions

Directions: Recast the following

sentences using the following phrases: 1. “would have liked to (do)”Notice: would have liked to (do) is used with the first person to express the speaker’s wish that was not fulfilled．1) I intended to go skating with you yesterday but I couldn’t because my mother didn’t let me.

(Response: I would have liked to go skating with you yesterday, but my mother didn’let me.)

2) I meant to sit in on Professor Wang’s class this morning but I didn’t because I had an important meeting to attend. (Response: I would have liked to sit in on Professor Wang’s class this morning, but I had an important meeting to attend.)

3) I intended to take part in the basketball match yesterday afternoon but I couldn’t

because I had a bad fall yesterday

morning.

(Response: I would have liked to take part in the basketball match yesterday afternoon, but I had a bad fall yesterday morning.)

4) I planned to lend you my cassette recorder, but I didn’t, because it was out of order.

(Response: I would have liked to lend you my cassette recorder, but it was out of order.)

2. should/ought to + perfect infinitive Notice:should/ought to + perfect infinitive, indicating a past obligation that was not fulfilled

1) The exhibition was a good one. All of us visited it except John. (Response: : John should/ought to have come with us.)

2) We all learned a lot from the lecture,

but Li didn’t attend it. (Response: : Li ought to/should have attended the lecture.)

3) The engineer went to the research institute without an umbrella and was caught in the rain.

(Response: : The engineer ought to/should have taken an umbrella with him.)

4) They bought a book for Mary but she didn’t like it.

(Response: : They oughtn’t to/shouldn’t have bought the book for Mary.)

needn’t + perfect infinitive

Notice: needn’t + perfect infinitive, indicating something that was unnecessarily done in the past

1) I wrote a summary in more than five hundred words. But the teacher only asked for