I didn't know if he would come.为什么要用过去将来时?

I didn't know if he would come.为什么要用过去将来时? 英语翻译说错 ,应该是I didn't know if he would come和i didn't know if h do you know if he will come为什么if后面用将来时 用过去将来时改写句子 Will the rain last long?(We didn't know...) I know he ____ tell you that he ____.A.didn't；would come B.d i didn't say he would come,did I didn’t think he would come,_____?填did I 还是would he I don't know if he ___(come) tomorrow.If he ____(come),I'll I don't know if he will come tomorrow. I don′t know if he come this afternoon I don't know if he ____ ( come ) I don't know if he will come tomorrow i think he if he free