I got simple questions

[Anonymous]

"Where do your grandfather come from?"

This one is correct expression, but if he's dead
then can I say

"Where did your grandfather come from?"

And the second question is I want to know
which one is correct.

"What are you thinking about my idea?"
"What do you think about my idea?"

Plz, help me.

[RonBee]

It should be: "Where does your grandfather come from?" If he is dead use did.

Say: "What do you think about my idea?"

[xydzp]

got it!