[正] He didn't have lunch at home yesterday.

3. 我能用be动词代替吗?

不管怎么说，含有行为(实义)动词的一般过去时的肯定句变成否定句或疑问句时，不能用be动词，必须用到did!含be动词的句子构成否定句或疑问句都绝不会让did露面! 例句：They went to the park last week. (改为否定句)

[误] They weren't go to the park last week.

[正] They didn't go to the park last week.