1.由少數及物動詞轉化來的不及物動詞(sell, clean, wash, cut, drive, wear, write等)，當句子的主語為物時，可用主動形式表被動意義。The car drives well.The cloth washes easily.2.在be worth doing, need doing中，主語是物，doing表示被動意義。The book is worth reading.The tree needs watering.3.形容詞 cheap, dangerous, important, comfortable, interesting等接不定式做狀語時，不定式的主動形式表被動意義。The old lady is easy to get along with.The question is difficult to answer.4.感官動詞look, sound, taste, smell, feel等，主動語態表被動意義。You look unhappy.
