點解 is/are 後面可以加 ed??

係passive voice即被動式

也很多是後面會既by

e.g. he is called by Mary (他被瑪莉打電話/瑪莉打電話給他)

is 是表達時式

e.g. is 是表達現在 ; was 是表達過去

called 是 call的過去分詞

1)is 和 are 之後用的verb一定是p.p.. E.g. is eaten, 不是 is ate.
2)若你寫作"The vase is broken by Ben." , 是因為你想強調 "The vase", 而不是 "Ben".

果只係"被動"句,,,is ate 係"被"吃的2c

This is passive voice.

2007-05-08 19:50:50 補充：
即係等於中文的被動句=]當你要個object做subject既時間就會用到=]E.G. This vase is broken by someone.這個花瓶被某人打破了同 Someone broke the vase係一樣不過係呢個係"把"