那就舉幾個例子看看吧.
(其實規(guī)則就是:在情態(tài)動詞后加上be,再將謂語動詞(實義動詞)變成過去分詞,其余就是平常的被動語態(tài)轉(zhuǎn)換,即將原句中的賓語變成主語,原句中的主語加上by之后變成狀語.)
1.Must
You must finish homework before supper.
改被動語態(tài):Homework must be finished (by you) before supper.
2.Should
Parents should teach children no later than 3 years old.
改被動語態(tài):Children should be taught by parents no later than 3 years old.
3.Have to
They have to hold a meeting in the park.
改被動語態(tài):A meeting has to be held by them in the park.
4.Can
Lily can carry that bookshelf easily.
改被動語態(tài):That bookshelf can easily be carried by Lily.
5.Need
Tom needs to train this dog everyday.
改被動語態(tài):This dog needs to be trained by Tom everyday.
希望可以幫助到你理解吧...