（误）They have married for two years.
（正）They have been married for two years.（表示已婚状态的持续，要用完成时的被动式。）
（误）He was laughed by all the pupils.
（正）He was laughed at by all the pupils.（不及物动词+介词=及物动词，变被动语态时介词不能省略。）
（误）English is difficult to be learned.
（正）English is difficult to learn.（英语难学=学英语难，也可说It"s difficult to learn English.原句的主语实际上是不定式的逻辑宾语，不定式要用主动形式。）
（误）Tom asked me if these islands are belonged to America.
（正）Tom asked me if these islands belonged to America.
（误）Great changes have been taken place in China.
（正）Great changes have taken place in China.