youshouldplayfootballfortoolong(改为否定句）you什么playfootballfortoolong

you shouldn't

SHOULDN'T

you shouldn't paly football for too long.
你不能玩太久足球

shouldn't=should not

You shouldn't play football too long . 比如should must need 等改否定句都是在这后面加not .

shouldn't

you shouldn't paly football for too long.

- - 再做这种题的时候，

试着用中文的思维去思考

这样 就不会弄混 should need must的区别了