The use 'to'

???? ?????? Hello! Could you please describe to(?) me cases when I should put 'to' before the 'me,you,us' and other words.Thx a lot!

to - the infinitive marker (e.g. "to describe");
to - a preposition (e.g. "a trip to the countryside", "ten minutes to nine", "she's kind to me", "add two to two");
to - an adverb (e.g. "she's fainted, bring her to").

I know that 'tell me' uses without 'to' . But 'say to me' uses with 'to'.
Could you please explain difference between these phrases. Why we can't use 'say to me' without 'to'?
Could you please tell me some examples where we should use something without 'to'