Looking on the internet deeply has found these results:

why have you decided to become a teacher? is the most popular phrase on the web.

why do you decide to become a teacher? 11 results on the web	why have you decided to become a teacher? 128,100 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
So why did you decide to become a nurse? And... you decide to become a wife. Why did you decide to become a surrogate? is it a lawyer, or does he want to become a doctor or a teacher? best chance is that he wants to become a dentist. And if you look at a guy called Dennis, when he decides what to become What made you decide to become a detective? All right, what made you decide to be a teacher?	And why have you decided to share this card with us now, Lesli? So, why have you decided to go on the pill? In hindsight, it did make me wonder why he suddenly decided to become a teacher. Why have you decided to tell the truth about Alison's alibi? Probably about the same time you decided to become a fugitive. So you decided to become a drug dealer. But why have you decided to come here? Why have you decided to take up the invitation to come to the European Parliament?

why do you decide to become a teacher?

11 results on the web

why have you decided to become a teacher?

128,100 results on the web

More popular!

And why have you decided to share this card with us now, Lesli?
So, why have you decided to go on the pill?
In hindsight, it did make me wonder why he suddenly decided to become a teacher.
Why have you decided to tell the truth about Alison's alibi?
Probably about the same time you decided to become a fugitive.
So you decided to become a drug dealer.
But why have you decided to come here?
Why have you decided to take up the invitation to come to the European Parliament?