she is back跟she come back有什么区别？？

区别就是she is back强调回来了这个状态、she come back是病句、she comes back强调回来的过程

第一句倾向于讲状态，
第二句倾向于动作。
但是第二句需要修改。
可以改成
She comes back.
She has come back.(已经回来)
She came back.(过去式)

第一句没错误
第二句有错误

没什么区别，不过第一句倾向于讲状态，第二句倾向于动作。第二句语法错误。你应该写she has come back.

she is back.强调回来的状态。
she comes back.强调回来的动作。