it was a bit difficult for me to answer to a yes-no question by saying
"Yes, I do."
or
"I do."
before I lived abroad and used english every day basis. I tended to say, simply,
"Yes"
or
"No"
to such questions, as the most Japanese would do. It's one way to answer but I found out saying
"I do"
might be better in some cases..
Ex.
Did you go see the movie ?
> I did.
Will you go back to your country ?
> I will.
I was confused when asked a negative question like,
> Didn't you bring that form ?
That's a difficult one for Japanese. If you did bring it, you should say "yes" but Japanese might say "no" for meaning "yes"... and I made these mistakes a lot, hahaha. To answer to such a question it's better or easier to say "(Yes), I did ( bring it)" as you make a full sentence to answer it, and I heard many said like "I did" for such a question.
Did you have a difficult time to answer to such a question or are you still having it ? LOL