as far as i know in formal speech you have verb endings like:
-습니다... e.g. 먹습니다, 옵니다...
-요... e.g. 먹어요, 와요...
someone who is above you in society may also use these forms while talking to you:
-네... e.g. 한국에 가네 in a statement
-나... e.g. 비가 오나? for questions
-게... as imperative
for informal speech you simply drop the ending -요:
덥다 : to be hot
polite versions: 덥니다 & 더워요
so you only take the converbalform of the infinitve before adding -요
hope that helps