英语过去时 什么时候要加were was?

来源：百度知道 编辑：UC知道 时间：2024/05/20 10:33:36
例句:The cups(?) made of plastic can be reused if we look after them well enough.
问号处要不要加were?

were想但于现在时的are
was相当于现在时的is
所以单数或第三第一人称用was，复数或第二人称用were

不要加，加了就两个谓语了

are的过去失是 were
is /am过去式是was

are的过去失是 were
is过去式是was

am \is --was
are ----were