There are four levels of formality for Korean proposals.
Formal (존댓말)
- 합시다 (hap-si-da)
- 해요 (hae-yo)
Informal (반말)
- 해 (hae)
- 하자 (ha-ja)
Let's go to that store:
그
| ku (that) |
가게 | ka-ge (store) |
에 | eh (to) |
가다 | ka-da (to go) |
- 그 가게에 갑시다. (ku ka-ge-eh kap-si-da)
- 그 가게에 가요. (ku ka-ge-eh ka-yo)
- 그 가게에 개. (ku ka-ge-eh kae)
- 그 가게에 가자. (ku ka-ge-eh ka-ja)
- The 합시다 style is mostly used among adults who are about the same age and are familiar with one another.
- The 요 ending might be used for gentle suggestions such as 같이 가요 (let's go together) to one the speaker doesn't know well. (Use the very polite form 같이 가세요 ka-chi ka-se-yo when speaking with someone much older.)
- The slightly less formal 하자 style is often used in place of the 해 form, perhaps because 해 sounds more like a command.
Remember that even though 존댓말 and 반말 are often referred to as the "polite" and "casual" styles, in reality neither style is necessarily always polite or not polite. The formal style can seem distant when used with a friend and is in fact used when people quarrel. And an inappropriately casual style in a formal situation can be perceived as impolite.