Question

what did his father do yesterday这个句子对吗？

Answer 1

不对，因为有“is”，be动词＋Ving，只有一般现在时才用“do”。 所以，应该为“what is his father doing？”或“what does his father do？” “what is his father doing？”意思是“他的父亲正在做什么？” “what does his father do？”意思是“他父亲是做什么的？” 注：be动词包括“is are am”。

Answer 2

从结构和时态上都是正确的。意思是：昨天你爸爸是干什么的？（翻译有些别扭！）把yesterddy换成in the past更合适。