"I give everything to him."
Translation:Tugaim gach rud dó.
The preoposition do doesn't have a fada.The number dó does, so they sound completely different.
Dó is only the numeral "2", and as such it is almost always preceded by a, as in a haon, a dó, a trí.
You do not use dó when specifying the number of things that you have - the Irish for "two 2's" is dhá dó. (An example where dó is not preceded by the article a).
dó is a also noun meaning "burn" - dó gréine means "sunburn".