1 包含was或者were，用wasn't或者weren't； I wasn't happy last week. They weren't happy at all that day. 2 不包含was或were的，用didn't，然后将句中的动词恢复为动词原形形式。 I didn't go to the park yesterday.
实义动词：didn't +动词原形（把原来的过去式改为动词原形） was/were: 改为：wasn't/weren't.如： He went to school yesterday.-He didn't go to school yesterday. He was at home yesterday.-He wasn't at home yesterday.
第2个回答 2017-08-22
----- I was a student. ---- I was not a student.(be动词） -----I went home. ----- I didn't go home.（实意动词）