If you aren't careful,you will have an accident.句子中的aren't可以改成don't吗?为什么一定要有be动词呢

If you aren't careful,you will have an accident.
句子中的aren't可以改成don't吗?
为什么一定要有be动词呢

不可以

aren't 改成 don't 要加be
if you don't be careful........

you change it for this:if you do not be careful...

句子中必须有主语和谓语， you aren't careful 中are 是谓语，改成don't后就没有谓语了...
改的话也可以，改成 in you don't be careful, you will have an accident 加个be做谓语就没错了