The function of the clausal connective ~고 is twofold. First, it simply connects two different clauses, regardless of their sequence. It corresponds to “and” in English. Consider the following examples:

제니퍼가 청소하고 매튜가 요리해요.

“Jennifer cleans up, and Matthew cooks.”

매튜가 요리하고 제니퍼가 청소해요.

“Matthew cooks, and Jennifer cleans up.”

Notice that the meanings of the sentences above are the same, even if the sequences of the clauses are different. Here are more examples:

머리가 아프고 졸려요.

“(My) head aches, and (I) am sleepy.”

존은 설거지를 하고 수잔은 텔레비전을 봐요.

“As for John, (he) washes the dishes, and as for Susan, (she) watches TV.”

앤이 일본으로 가고 팀이 한국으로 가요.

“Ann goes to Japan, and Tim goes to Korea.”

제임스가 경제학을 전공하고 이사벨이 생물학을 전공합니다.

“James majors in economics, and Isabel majors in biology.”

Second, ~고 links two sequential actions or events, equivalent to “and then” in English. Consider the following examples:

숙제를 하고 점심을 먹어요.

“(I) do the homework and then eat lunch.”

점심을 먹고 숙제를 해요.

“(I) eat lunch and then do the homework.”

Notice that ~고 indicates the order of the action. In other words, the change in the sequence of the clauses generates a different meaning. Here are more examples:

79저녁(을) 먹고 집에 갈 거예요.

“(We) will eat dinner and then go home.”

샤워(를) 하고 자지요?

“(You) take a shower and then go to bed, right?”

꼭 손(을) 씻고 요리하세요.

“Surely, wash (your) hands and then cook.”

장보고 집에 가자.

“(Let’s) do grocery shopping and then go home.”

~고 is subject to one restriction. It is not conjugated for the tense. Consider the following examples:

아침(을) 먹고 마트에 갔어요.

“(I) ate breakfast and then went to the mart”

어제는 날씨가 흐리고 추웠습니다.

“As for yesterday, the weather was cloudy and cold.”

Notice that both sentences are about the past action and state. However, the past tense is not marked by the ~고 ending clauses but by the main clauses.