语法分析：I'll just assume you said what I thought I heard you sa

“我假定你说了我认为我听见了的你说的话”
（1）I是主语,assume是谓语,you said what I thought I heard you say是宾语从句.
（2）而在you said what I thought I heard you say里面,第一个you是主语,said是谓语,what I thought I heard you say是宾语从句.
（3）在what I thought I heard you say里,I thought I heard 都是用来修饰what you say的.在what you say里,you是主语,say是谓语,what是宾语.