Ch7 情態助動詞 Modal Auxiliary Verb

• 本章用到的情態助動詞 

助動詞+ V原
can
could
may
might
shall
should
had better
must
will
would

ought to

助動詞+to+ V原

have to
have got to //避免縮寫誤認, he's got ; 沒有had got
be able to
ought to

• will & shall

現在只有We和I會跟shall，he、she、they不會跟shall。

I will 表示願意
I shall  沒有願意,強迫將會去, 例如小孩說 : I shall go to school tomorrow.

• can & could

can= be able to , 過去式could

• may might Maybe(adv字首) 表示可能性

• may can 允許

• could

如為過去表示能力

Could you speak English?

如為現在、未來表可能性

You could be win.
It could start raining

• May I、Could I 、 Can I 禮貌問句 (以自身開始問) p.s may 不能用you

高 <===========>低

通常說出人名用can I 問， 不熟的用May I 如有Mr, Ms, Sir....

May I ask who is calling?

• would you、 Could you 、will you 、can you 禮貌問句(問別人) , would 不能用 I

高 <===========>低

Would you please keep voice down?

• should=ought to = had better 表示建議

should <ought to < must 語氣強度

用ought to 情況
1. recommend /advise
You ought to exercise more.

2.probability/high chance
She ought to receive the package tonight.

3..regret
I ought to have studied medicine not a pharmacy.

否認/ 問句 (沒有 'to')
Ought she call the police?
You ought not (to) smoke so much.

• Have to = Have got to = Must 表示必須

have to 比較常用於口語, 書寫

must 用於警告

have got to 非正式口語

問句為 Do/Does S(主詞) have to ....? (問句少用must, have got to

• Must not 禁止

Bus Passengers must not talk to the driver.

• Must 可用於推論 , 表示必須

Amy play tennis every day. she must like to play tennis.

• 祈使語 (字首 V原, 也可以在字首字尾加上please)

命令、請求、指示

Keep the engine running

• Prefer

Prefer + N / Ving

I prefer having afternoon tea.
I prefer coffee

Prefer V-ing to V-ing or Prefer N to N
喜歡前者 多於 後者

 I prefer playing baseball to playing basketball. 
 I prefer Paris to London


介係詞 to 也可用 over

 I prefer cake over cookie. 

喜歡做某事勝過另一件事

prefer + V-ing1 + to + V-ing2  
= prefer + to V1 + rather than + V2 
= prefer + to V1 + instead of  + V-ing2
= would rather + V1 + than + V2

Amanda prefers cooking at home to eating at restaurants. 

=Amanda prefers to cook at home rather than eat at restaurants.

=Amanda prefers to cook at home instead of  eating at restaurants.

=Amanda would rather cook at home than eat at restaurants.

「prefer + that 子句」為「假設語氣」,that 子句中「V原形」或「should + V」

Amanda prefers that John remove his shoes before entering her home.


would V原 rather  V原

Tom would read rather  talk 


like V-ing better than V-ing 
= lIke N better than N

I like playing outside better than staying at home.