I think l have no change对吗?问一下大家‘‘我想我没有变化（在暑假中）应该怎么写?change需要用过去式吗?I think l have no change．这句话对吗?

不行，他们都回答错误。
应该是 i think i have not changed.

可以,但是不地道
I I think l did not have any chang.

没错,have+n.不是动词

可以说：
I think I have no change.
也可以说：
I think I haven't changed at all.

在类似主观愿望的宾语从句中,无论否定词在主句还是从句,英语更习惯把否定词提前到主句,
此外,change变化,多用there be 句型倒装阐述
所以,正规的说法是
I don't think there is any change on me.

最好用复数，change是个可数名词,时态最好用过去时，因为暑假已经过去了
I think i had no changes.
也可用现在完成时
I think I haven't changed.