Dare, meaning have the courage to do something, can also be used in two ways:
Dare的意思是“有勇氣做某事”，它也有兩種用法：
dare 作實義動詞
* as an ordinary verb followed by an infinitive with to, with s in the third person singular and with questions and negatives formed with do:
作為實義動詞時，接帶to的不定式，第三人稱單數作主語時加s，疑問句和否定句用do來構成：
He never dares to criticise her for wasting money and she doesn't dare to interrupt him when he's working.
他從不敢批評她浪費錢，而她不敢打擾他工作。
dare 作情態(tài)動詞
* as a modal auxiliary verb followed by an infinitive without to, with no third person singular s and with questions and negatives without do:
作為情態(tài)助動詞時，接不帶to的不定式，第三人稱單數作主語時不加s，疑問句和否定句不需要用do來構成：
Dare she tell him what she thinks about him? She daren't say anything. He will only shout at her. "How dare you speak to me like that?" he will say.
她敢告訴他她對他的想法嗎?她什么也不敢說。他只會對著她咆哮：“你怎敢那樣對我說話?”他肯定會這么說。
比較
Differences in use are not as fixed or clear cut between doesn't dare to and daren't as they are between doesn't need to and needn't, except in expressions or collocations such as:
doesn't dare to與daren't在用法上的差別不像doesn't need to和needn't那么固定或清晰，除了在以下這些表達和搭配中：
* How dare you?
你怎么敢?
eg: How dare you walk away when I'm talking to you?
我在跟你說話的時候你怎么敢走開?
* I dare you to…
我諒你不敢……
I dare you to go up to him and ask him for a date.
我諒你也不敢走到他面前請他跟你約會。
* I dare say…
我敢說……
I dare say you're pretty hungry after all that cycling.
我敢說你騎了那么久后肯定餓死了。
In this last example, I dare say means I suppose.
最后一例中的I dare say的意思是I suppose，我料想。
小升初英語語法零基礎：情態(tài)動詞can與may的用法
情態(tài)動詞
情態(tài)動詞有一定的詞義，但詞義不完全，須同動詞原形連用;
情態(tài)動詞沒有人稱和數的變化;
疑問句直接把情態(tài)動詞提前，否定句在情態(tài)動詞后面加not。
*情態(tài)動詞中有一類是具有情態(tài)動詞特征的詞，如have to，但它有人稱、數的變化，它的疑問句和否定句的構成方式也和其他情態(tài)動詞有所不同。
can 的用法
一、表能力，有“能，會，能夠”的意思。例如：
-Can you drive a car? 你會開車嗎?
-Yes, I can. 我會。/ No, I can't. 我不會。
二、表允許，在口語中代替may，有“可以”的意思。
(見下面 may 的用法第四點)
三、表示可能性，常用于否定句和疑問句。例如：
Can it be true? 那會是真的嗎?
Today is Sunday. He can't be at school. 今天是星期天，他不可能在學校里。
很多同學都不太清楚 can 與 be able to 的異同吧，趕快來學習一下吧
may 的用法
一、表示許可或征求對方的許可，有“可以”的意思。例如：
You may go now. 你可以走了。
May I use your computer? 我用一下你的電腦可以嗎?
二、回答以 may 開頭的疑問句有如下表達法：
-May I smoke here? 我可以在這兒抽煙嗎?
-Yes, you may. / Yes, please. 請抽吧。
-No, you can't. / No, you mustn't. / No, you'd better not. 請不要抽煙。
三、表示猜測，通常只用于陳述句。例如：
You may be right. 你可能是對的。
四、在口語中 can 可以代替 may 表示許可，但 can 較隨便，may 更正式。例：
Can I use your bike, John? 約翰，我可以用一下你的自行車嗎?
May I have a look at your license please, sir? 先生，我可以看一下你的執(zhí)照嗎?
