名词性从句i thought about （what you say）.意思是你说过的吗？为什么

what you say做介词about的宾语what you say是一个名词性从句
意思是你说过的我都想过

I think about what you have said 这句话是正确的

上面的i thought about （what you say 不对

因为我考虑的是你说过的话，那已经过去了，就不能用一般现在时了

I think about what you said