改错 Please turn these Chinese sentences in English,will you?

题目

改错 Please turn these Chinese sentences in English,will you?
I didn't know there used to have a new train station there.
How long have you become an English teacher?
We haven't seen each other since many years.
The alone traveler found himself alone after he woke up.

答案

I didn't know there used to be a new train station there.
How long have you been an English teacher?
We haven't seen each other for many years.
The alone traveler found himself lonely after he woke up.