把主動語態(tài)改為被動語態(tài)，可以遵循以下幾個步驟： 把賓語變成被動語態(tài)中的主語； 找出謂語動詞，變成相應(yīng)的被動。如：一般式變成be done。過去式變成was/were done； 把主語變成介詞by 的賓語； 注意人稱、時態(tài)和數(shù)的變化。 例： Bruce writes a letter every →A letter is written by Bruce every Li Lei mended the broken bike this →The broken bike was mended by Li Lei this He has written two novels so →Two novels have been written by him so They will plant ten trees →Ten trees will be planted by them Lucy is writing a letter →A letter is being written by Lucy You must lock the door when you →the door must be locked when you