文档介绍：情态动词can . should
情态动词有can (could), may (might), must, have to, shall (should, will (would), dare (dared), need (needeis be true?
“not”
I can not speak English. We can not swim. He can not sing.
You can not play the guitar. She can not draw. They can not dance.
变一般疑问句直接把can提前, 肯定回答用yes, 否定回答用no.
注意can提前后首字母大写
例Can you speak English? Yes, I can. /No, I can’t.
Can you play the guitar? Yes, we can. / No, we can’t.
Can she draw? Yes, she can. /No, she can’t.
Can he sing? Yes, he can./ No, he can’t.
Can they dance? Yes, they can./ No, they can’t.
总结：
情态动词can，后面总是接动词原形,”能,会”.
用法口诀：
情动can表能力, 和行为动词不分离.
不管主语如何变, can的模样永不变.
只要出现情动can, 动词原形后面站.
一般疑问can提前, 否定can后not添.
Should
。其意为“应该”
He should work harder. 他应该更加努力。
You should help your mother with the housework. 你应该帮你母亲做家务。
【注】should表示推断时，语气较肯定，通常是指非常可能的事(因为暗示有一定的事实依据或合乎常理)
Should I wear a coat? 我要穿大衣吗？
表示推断。意为“应该”、“可能”
He should arrive soon 他可能很快就到了。
The train should have already left. 火车大概已经走了。
The concert should be great fun. 音乐会应该很有意思。
should 用于征求意见主要用于第一人称的疑问句形式
Should I open the window? 我可以打开窗户吗？
Where should I meet you tonight? 我今晚该到哪儿与你见面？
What should we do now? 我们现在该干什么呢？
should 表示谦逊或委婉。通常与like, love, think, say, imag