Since there is already a question for , I'll add my two cents for .
I think and have clear distinct uses. means "to meet", as in
> .
> I went to see my mother.
This type of meeting someone is usually planned. (Of course can mean more than meeting some _one_ , but these uses are not comparable to any longer.)
means "to come across, to meet by accident, to encounter", e.g.
>
> Sorrow is at parting if at meeting there be laughter.
The just means what it always means and the structure of is just -stem + verb, like in , , etc. I don't think it's too far a stretch to imagine that "to go out and meet" came to mean "to encounter" or "to meet by accident".