Propositive? It means you're proposing something. Marriage? Could be. If your Korean gets good enough you may propose to a Korean. I've seen it happen multiple times.

Anyway, we'll use the ㅂ시다 ending. You can propose a lot of things: "Let's go to the store", "Let's dance", "Let's go fishing". Here are some examples (the vowel-consonant rules apply):



같이 영화를 봅시다. Let's see a movie together. (together movie see-let's)

식사 합시다. Let's eat. (meal do-let's)

열심히 공부합시다! Let's study hard! (diligently study-let's)

결혼합시다! Let's get married! (marry-let's)