A short while ago,however,he became a bus driver a

网友回答

这句话本身就不对.
应该是：he became a bus driver and he does not regret it.
regret本身可以作为动词或者名词.在此句中做谓语动词.
楼下,he does not regret it 和 he did not regret it都没错.这是两个并列的单句.谓语不一定是同一时态.时间上既可以是同时,也可能先后.就这个来说既可以是现在不后悔的he does not regret it,也可以是当时就不后悔的he did not regret it.
======以下答案可供参考======
供参考答案1:
这是个病句。regretted和be动词重复。可以改成he didn't regret it.
供参考答案2:
1楼虽说得没错，可是改的也是病句啊，应该是he didn't regret it. 吧
供参考答案3:
然而就在前不久,他开上了公共汽车,他并不为此而感到后悔。