改否定句分两种情况:
1. 谓语动词为be动词,be动词包括am, is, are以及他们的过去式was, were;
改否定直接在be动词后加not即可。
2.为实义动词,如do, make, go, come等。
在动词前加don't, 若是过去式,则是加didn't。
希望可以帮助到你^^
:)
They were not students. 这是一般过去式,是主谓宾的句式,直接在系动词后面加not就行了
They weren't students.
They were not students.
系动词后面加not