It is my fault还是It was my fault（因为错误已经发生了,但我发现很多例句都用了is）

It is all my fault it was my fault和 it is my fault有什么区别,还是说只有一种是正确的. It's my fault, It is my fault还是It was my fault（因为错误已经发生了,但我发现很多例句都用了is） It's not my fault还是that's not my fault It’s not my fault. Sorry!it is all my fault.Could you forgive me? This is not your fault it was my fault, I for give you 什么意思 It is not your fault This is my fault.与 It is my fault.有什么区别.this is 与 it is 分别在什么情况下使用? feel so sorry,I have to admit it is my fault .just forget it . Is my feelings in trouble!Perhaps it is my fault!good night. It's my fault,please pardon me It's my fault ,I'm sorry. It's all my It's all my fault It is on one fault怎么改正 描述某个意思时,什么情况下用 it's ,什么情况下用 there's 如it's my fault 还是 there's my fault It's not my fault可不可以改成It isn't my fault?