I would appreciate any imput that someone can give me regardin this question.
I am trying to figure out what tense this verb is in.
I don't know him, I don't think (is this the verb "think") of him. He doesn't exist.
I am also having trouble figuring out the tense and the aspect in this sentence.
He won't understand (verb) all the gravity of this fact to us.
"I do not know" = the present tense of the auxiliary verb "do" + the adverb "not" + the infinitive "know". In effect, it's the present tense.
"He won't understand" = the present tense of the auxiliary verb "will" + the adverb "not" + the infinitive "understand". It's the future tense.
(By the way, it's input, not imput!)