“is” 的过去式是 was 或 were，具体用哪个取决于主语是单数还是复数。

* 例如：He was happy. (他很开心。)

* She was tired. (她很累。)

* The book was interesting. (这本书很有趣。)

* 例如：We were at the park. (我们在公园里。)

* You were late for school. (你上学迟到了。)

* The kids were playing. (孩子们在玩耍。)

是不是很简单？记住了，只要区分主语的单复数，就能轻松搞定 “is” 的过去式了！