shall和 shaw的区别

1、shall与第一人称连用，表示一般将来时，否定形式为shan't；will则适用于各种人称。
I shall be in touch with you again shortly.
It'll be our first holiday for years.
2、用于第二、三人称陈述句，表示意图、决心、命令、警告、允许、威胁等语气，可译为“必须、应、可”等。
The interest shall be divided into five parts, according to the agreement made by both sides.，declared the judge.（与第三人称连用，表示决定，译为“一定要”）
You shan't use my computer if you don't take care of it.（与第二人称连用，表示警告）

3、shall 用于第一、三人称的疑问句，表示征询对方意见和请示。
Shall he come in or wait outside
Shall we make it next Saturday
二、should的用法
1、should 在肯定句中表示劝告、建议、命令，可译为“应该”，其同义词是ought to 。
I often see lights in that empty house. Do you think I should report it to the police？
2、should + have done sth. 用在肯定句中表示本应该做而未做的事情，译为“本应该”；用在否定句中表示过去本不应该做却做了的行为，可译为“本不应该”，含有委婉的批评、责备之意。
Mr. White should have arrived at 8:00 for the meeting, but she didn't show up.
3、should 也可表示推测，可译为“应该会、想必是，可能”，是说话人按照常理或职责进行的推测。（而must是进行上下文有根据的肯定推测，can, could 则用于否定句和疑问句中表达推测语气；might表达最小的可能性，语气也最弱）
Bus No. 60 comes every ten minutes, and there should be one coming.
4、用在名词性从句中，表示惊异、意外等情绪，常译为“竟然”。
（1） You can't imagine that a well behaved gentleman should be so rude to a lady.
（2） Well, I could never imagine an honest boy like John, should cheat in the exam!
5、should 在虚拟条件句中的运用。
（1）用在command, demand, desire, insist, order, request, require, suggest (表建议)等表要求、命令、建议类的动词后，宾语从句中用should+动词原形构成虚拟语气,且should常可省略；或者有这些词的其他形式出现的表语从句，同位语从句或主语从句中具有相同的用法。
The doctor suggested that she (should) stay in bed for a few days.
The captain gave an order that all the heavy things (should) be thrown away.
（2）should 用于对将来进行虚拟的条件句中Should it rain tomorrow, the sports meeting will be called off.
6、should 用于if和in case 之后，表示某事不太可能发生，常译为“万一”，“以防……”。
If you should change your mind, do let me know.
Take your umbrella with you, in case it should rain.