should，would，could，must，might，may，can的區別：
1、can (could)表示能力，could主要指過去時間。表驚異、懷疑、不相信等態度。主要用於否定句、疑問句或感嘆句中。
2、may (might)表允許，might可以指過去時間，也可指現在時間，語氣更委婉。在回答以may引起的問句時，多避免用這個詞，而用其它方式，如Yes, please. / Certainly.表可能（事實上）。可以指過去時間，也可以指現在時間，但語氣更加不肯定。
3、must表示義務。意為“必須”（主觀意志）。表示揣測。意為“想必、準是、一定”等，只用於肯定句。
4、 shall表徵詢意見，用於第一、第三人稱疑問句。表說話人的意願，有“命令、允諾、警告、決心”等意思，用於第二、第三人稱陳述句。
5、will表意願，用於各種人稱陳述句。表請求，用於疑問句。表示某種傾向或習慣性動作。
6、should表義務。意為“應該”（某件事宜於做），用於各種人稱。表推測，意為“想必一定、照說應該、估計”等。
7、would表意願，表委婉地提出請求、建議或看法。表過去反覆發生的動作或過去的一種傾向。
拓展資料
should
1、I should exercise more
我應該多鍛鍊一些。
2、All visitors should register with the British Embassy
所有遊客都必須到英國大使館登記。
3、I should have gone this morning but I was feeling a bit ill
今天早晨我本應該走的，但是我覺得有點不舒服。
4、You should have no problem with reading this language
閱讀這種語言你應該沒問題。
5、Should I or shouldn't I go to university?
我該不該去上大學呢？
would
1、No one believed he would actually kill himself
沒有人相信他真的會自殺。
2、The statement added that although there were a number of differing views, these would be discussed by both sides
這項宣告還稱，雖然雙方觀點存在若干分歧，但將就這些分歧展開討論。
3、Ordinarily it would be fun to be taken to fabulous restaurants
一般來說，跟別人去豪華餐館吃飯會是件樂事。
4、They said they would give the police their full cooperation
他們說他們願意與警方通力合作。
5、She asked me what I would like to do and mentioned a particular job
她問我想幹什麼，然後提到了一份工作。
could
1、For my return journey, I felt I could afford the extra and travel first class
至於回程，我覺得我能多花點錢坐頭等艙。
2、Though he had a temper and could be nasty, it never lasted
雖然他愛發脾氣，而且有時還很討厭，但向來都只是一陣兒。
3、He could have made a fortune as a lawyer
他本可以當律師掙大錢的。
4、Doctors told him the disease could have been caused by years of working in smokey clubs
醫生們告訴他這種疾病可能是由於多年在煙霧繚繞的俱樂部工作所致。
5、Their hope was that a new and better East Germany could be born
他們希望能夠誕生一個嶄新的、更加美好的東德。
should，would，could，must，might，may，can的區別：
1、can (could)表示能力，could主要指過去時間。表驚異、懷疑、不相信等態度。主要用於否定句、疑問句或感嘆句中。
2、may (might)表允許，might可以指過去時間，也可指現在時間，語氣更委婉。在回答以may引起的問句時，多避免用這個詞，而用其它方式，如Yes, please. / Certainly.表可能（事實上）。可以指過去時間，也可以指現在時間，但語氣更加不肯定。
3、must表示義務。意為“必須”（主觀意志）。表示揣測。意為“想必、準是、一定”等，只用於肯定句。
4、 shall表徵詢意見，用於第一、第三人稱疑問句。表說話人的意願，有“命令、允諾、警告、決心”等意思，用於第二、第三人稱陳述句。
5、will表意願，用於各種人稱陳述句。表請求，用於疑問句。表示某種傾向或習慣性動作。
6、should表義務。意為“應該”（某件事宜於做），用於各種人稱。表推測，意為“想必一定、照說應該、估計”等。
7、would表意願，表委婉地提出請求、建議或看法。表過去反覆發生的動作或過去的一種傾向。
拓展資料
should
1、I should exercise more
我應該多鍛鍊一些。
2、All visitors should register with the British Embassy
所有遊客都必須到英國大使館登記。
3、I should have gone this morning but I was feeling a bit ill
今天早晨我本應該走的，但是我覺得有點不舒服。
4、You should have no problem with reading this language
閱讀這種語言你應該沒問題。
5、Should I or shouldn't I go to university?
我該不該去上大學呢？
would
1、No one believed he would actually kill himself
沒有人相信他真的會自殺。
2、The statement added that although there were a number of differing views, these would be discussed by both sides
這項宣告還稱，雖然雙方觀點存在若干分歧，但將就這些分歧展開討論。
3、Ordinarily it would be fun to be taken to fabulous restaurants
一般來說，跟別人去豪華餐館吃飯會是件樂事。
4、They said they would give the police their full cooperation
他們說他們願意與警方通力合作。
5、She asked me what I would like to do and mentioned a particular job
她問我想幹什麼，然後提到了一份工作。
could
1、For my return journey, I felt I could afford the extra and travel first class
至於回程，我覺得我能多花點錢坐頭等艙。
2、Though he had a temper and could be nasty, it never lasted
雖然他愛發脾氣，而且有時還很討厭，但向來都只是一陣兒。
3、He could have made a fortune as a lawyer
他本可以當律師掙大錢的。
4、Doctors told him the disease could have been caused by years of working in smokey clubs
醫生們告訴他這種疾病可能是由於多年在煙霧繚繞的俱樂部工作所致。
5、Their hope was that a new and better East Germany could be born
他們希望能夠誕生一個嶄新的、更加美好的東德。