Module 5 Rules and suggestions
---- yes, you can. (no, you can’t / mustn’t. )
用may i...？征徇對方許可時比較正式和客氣，而用can i...？在口語中更常見。
2）用于祈使句，表示祝愿。 例如：
may you succeed!
3) 表示推測、可能性（不用于疑問句）。might不是過去式，它所表示的可能性比may小。 例如：
he may /might be very busy now.
your mother may /might not know the truth.
3. must, have to
1) 表示必須、必要。例如：
you must come in time.
在回答引出的問句時，如果是否定的，不能用mustn’t（禁止，不準），而用needn’t, don’t have to（不必）。例如：
---- must we hand in our exercise books today?
---- yes, you must.
---- no, you don’t have to / you needn’t.
2) must是說話人的主觀看法，而have to則強調客觀需要。must只有一般現在時，have to 有更多的時態形式。 例如：
his play isn’t interesting, i really must go now.
i had to work when i was your age.
3) 表示推測、可能性（只用于肯定的陳述句）例如：
you’re tom’s good friend, so you must know what he likes best.
your mother must be waiting for you now.
4. dare, need
1) dare作情態動詞用時, 常用于疑問句、否定句和條件從句中, 過去式形式為
dared。例如：
how dare you say i’m unfair?
he daren’t speak english before such a crowd, dare he?
if we dared not go there that day, we couldn’t get the beautiful flowers.
2) need 作情態動詞用時, 常用于疑問句、否定句。在肯定句中一般用must, have to, ought to, should代替。 例如：
you needn’t come so early.
---- need i finish the work today?
---- yes, you must. / no, you needn’t.
3) dare和 need作實義動詞用時， 有人稱、時態和數的變化。在肯定句中，dare后面常接帶to的不定式。在疑問句和否定句中，dare后面可接帶to或不帶to的不定式。而need后面只能接帶to的不定式。 例如：
i dare to swim across this river.
he doesn’t dare (to) answer.
he needs to finish his homework today.
5. shall, should
1) shall 用于第一人稱，征求對方的意見。 例如：
what shall we do this evening?
2) shall 用于第二、三人稱，表示說話人給對方的命令、警告、允諾或威脅。
you shall fail if you don’t work hard. (警告)
he shall have the book when i finish it.(允諾)
he shall be punished.(威脅)
6. will, would
1) 表示請求、建議等，would更委婉。例如：
will / would you pass me the ball, please?
2) 表示意志、愿望和決心。例如：
i will never do that again.
they asked him if he would go abroad.
3) would表示過去反復發生的動作或某種傾向。would表示過去習慣時比used
to正式，且沒有“現已無此習慣”的含義。例如：
during the vacation, he would visit me every other day.
the wound would not heal.