And Then (-고)

The connective ending -고 links two clauses together in a sequential or additive relationship. It attaches directly to the verb or adjective stem regardless of whether it ends in a vowel or consonant. When describing sequential actions, -고 implies one action happens after another: 손을 씻고 밥을 먹었어요 (I washed my hands and then ate).

Unlike -아/어서, the subject of each clause connected by -고 can be different. You can also use different tenses in each clause. This makes -고 one of the most flexible connective endings in Korean. It is commonly used in both spoken and written language.

At TOPIK Level 3, learners should be comfortable using -고 in longer, multi-clause sentences and distinguishing it from other connectors like -아/어서, which implies a causal or inseparable sequence.