Should I use I forgot or I forget?

Dear,
It is puzzling. I think they must be used in a suitable situation.
"I forget his name" means I usually do this.
"I forget we have homework tonight" means the agreement of the tense
"I forgot what to do"means I did the action in the past.
In my opinion;
I forget/forgot his name.
I forgot we would have homework tonight.
I forgot what to do/what I should do.
I don't think that I can persuade you like this. It is not our language.

1. forget

2. forget

3. forget

   forget 和forgot主要是时态的问题，attach to timezone，you can charge timezone first .and then decide to use forget or forgot

I ___forgot__ his name (when I still can't remember)
I___forgot___we have homework tonight
I____forgot__what to do, can you tell me again?

It all depends on what kind of meaning you want express. If you want to give out the impression that it has already been for some time you didn't remember sth, then you use ‘I forgot’. And if you want...

1，I forgot
2, I forgot
3, I forget