when were these houses built ?

Question

when ___ these houses built

這一題選擇題我搞不懂

(1)were(2)have

為何不能用have

如果選1 那後面的動詞built 不就要改成ing

有誰可以告訴我T__T

已更新項目:

be+pp=被動

讀的有點眼花沒注意到這點

我比較想知道這題能不能用have

不能用的原因在哪?

有人能幫我解答@@

Answer 1

最佳解答

不能用have，因為have built就成了主動態的動詞，和本句的主詞houses不相容了。因為houses不會造東西，而是被造的。

用be當助動詞才能幫動詞形成被動態。

用have當助動詞則形成主動態的完成式。

Answer 2

To Leo:

"When these houses have been built"不是完整句子

完整的句子是:

1. When were these houses built?

2. Since when have these houses been built? (少了Since, 時態就不正確)

Answer 3

When were these houses built = When these houses have been built