for what reason 可不可以用why来代替?

题目

for what reason 可不可以用why来代替?
就划线部分提问：
Our English teacher is on a friendly visit to Canada.
能不能说：Why is your English teacher going to Canada?

答案

可以用"why" 但应该是
Why does your English teacher go to Canada?
这里的"does" 不能用"is"代替.后面的动作时态也要变下.