can和could是我們最常用來表達”可以“的意思,而且之前的文章有講過can和could分別是使用於現在時態和過去時態,那除了這兩點,是否還有其他區別?它們和be able to 又有什麼關係?
Can
我們用can表達事情是可能的,或者某人有能力做某件事情。表達的結構為:
can+動詞(can do/ see/ eat......)
我們可以從客廳看見那個公園。
He can speak four languages.他可以說四種語言。
有時候我們也會用be able to 表示”可以“,但是can 更常用一些,不過在現在完成時中,都是用be able to 來表示。
Tom 無法入睡。
Tom 無法入睡。
Tom haven't been able to sleep recently.(現在完成時態)Tom最近無法入睡。
Can的否定形式是:can not/ can't,表示”不能“。
I can't come to the party on Saturday.週六的派對我去不了。
同樣,can't 也可以表示”覺得某事不可能“
You can't be hungry, you've just had lunch.你不可能餓了,你才剛吃完午飯。
而表示”確定某事是真的“,則使用must。
Mike: Oh, it must be very noisy.(噢~那肯定很吵)
Could
之前有講過,could是can 的過去時態,用於過去式的句子中,同樣表示”可以“。它經常跟see,hear,smell,taste,feel,remember,understand一起使用:
He spoke in a very low voice, but I could still understand what he said.他用很小的聲音說話,但是我還是能夠明白他的意思。
When we went into the house, we could smell the buring from the kitchen.當我們走進房間的時候,可以聞到從廚房傳來的燒焦味。
除了作can的過去式使用,could也可以表示”可能“,類似於may/ might。
The phone is ringing, it could be Jill.=The phone is ringing, it may/ might be Jill.
電話響了,可能是Jill打來的。
The weather is nice now, but it could change later.=The weather is nice now, but it may/ might change later.
現在天氣很不錯,但是一會可能會變天。
但是,couldn't 是不同於may not和might not的。
She couldn't have seen you, because she was too far away.她不可能看到你,因為距離太遠了。
She might not have seen you.她可能沒有看到你。
疑問句中的Can/ Could/ Would...?
在表達”請求“”提出要求“”許可“”邀請“的問句,通常分別使用Can,Could,Would。
請求別人做某事時,經常使用can或者could:
I wonder if you could help me.Can/ Could you wait a moment, please?Can you do me a favour?Could you tell me how to get to the station?想要某些東西的時候,可以使用Can I have.../ Could I have...:
Can I have these stamps, please?我可以拿這些郵票嗎?
Could I have a cup of tea, please.我想要一杯茶
在請求許可時,可以使用 Can,Could,May:
Can I speak to Tom, please?May I come in? --Yes, please.允許別人做某事時,最常用Can:
Yes, you can use the phone.是的,你可以用這部電話。
主動提出想要做某事時,可以用Can I...?:
Can I help you?Can I give you something to drink?邀請別人時,我們可以用Would you like...?:
Would you like to come to dinner tonight?--"Yes, I'd love to."