도

too, also, even

Adds something to what is already true: "too", "also", "as well" — she has big eyes and is tall too, we talk about worries and joke around too. With a negative or something unexpected it shifts to "even" ("won't even welcome you"). It takes the place of the subject and object markers rather than stacking on top of them, so a word that would have carried 이/가 or 을/를 simply carries this instead.