내가 왜 거짓말을 했을까?

[Pavel Bond]

내가 왜 거진말을 했을까?
Why I said a lie?
But why not just
내가 왜 거진말을 했어요?

 

[Rigardo Lee]

내가 왜 거짓말을 했을까? is a correct expression of it, which is "why did I lie?" in English.

 

[Pavel Bond]

Thanks!