Modal verbs
Can / Could Can – могу, умею. Саn / Could - не могли бы вы (вежливая просьба) I can sing. Can you sing? I cant sing. Could you open the window?
Should Следует. Употребляется, когда хотят дать совет, порекомендовать сделать что-то. You should go and see this film. It is very interesting. You should not come home so late.
Should / Should not Close the window, turn the gas off, turn the gas on, put the knife in the drawer, turn the water off, play with matches.
Must Должен, обязан. Употребляется, если хотят отдать указание, заставить человека, сделать, что-то. You must come home at five. John must not eat ice-cream. He is ill. Must I wash the floor?
Must not / should
May Разрешите. May I use your bike? May I sit here? May I come in?