같이
gati · TOPIK 1
together
같이 = 같 (same) + 이 (adverb ending): in the same way, hence together
From the adjective 같다, to be the same, plus the adverb-forming suffix 이. Doing something the same as someone gives both meanings: like/as, and together. Pronounced gachi, because ㅌ before 이 softens to a ch sound.