‘-은데/ㄴ데, -는데, -인데’ is used with a verb. The second clause combines with an imperative or a propositive sentence ending, and the first clause explain the situation of the order or proposal.
● 피곤한데 좀 쉴까요? (We’re tired. Can we take some rest?)
● 이거 쉽지 않은데 좀 가르쳐 주세요. (This is not easy. Please teach me.)
‘-으려고/려고’ is used with a verb to express in order to do something or intention/purpose. It’s never used with future tense.
● 컴퓨터를 사려고 돈을 모았어요.
● 친구한테 주려고 선물을 샀어요.
● 이제 담배를 좀 끊으려고요.
‘-어야/아야/여야 하다(되다)’ shows obligation/necessity and can be used with any verb.
– tense is normally expressed in the final 하다(되다).
– negation is normally expressed in the main verb.
● 집에서 푹 쉬셔야 합니다.
● 해외여행을 하려면 여권이 있어야 해요.
● 내일 뭘 가져와야 해요?
‘-기 때문에’ is used with a verb showing a reason. It’s often used in a written form rather than in spoken language. It cannot be used in an imperative nor in a propositive sentence. It can be used with a noun like ‘N 때문에‘, And it can be used with a past tense.
● 한국 음식을 좋아하기 때문에 자주 먹습니다. (Because I like Korean food, I often eat Korean food.)
● 눈 때문에 학교에 못 갑니다. (Because of snow, I cannot go to school.)
‘-은/ㄴ 지’ is used with a verb, showing a certain period of time has passed after the performance has been done in the first sentence.
● 저는 결혼한 지 10년 됐어요. (I’ve been married for 10 years.)
● 한국에 온 지 8개월 됐어요. (It has been 8 months since I came to Korea.)
‘-어지다/아지다/여지다’ indicates the changes occurring to the state or condition of the subject.
● 날씨가 추워지고 있어요. (Weather is getting colder.)
● 한국 생활에 익숙해졌어요. (I got used to Korean living.)
‘-어도/아도/여도’, having similar to ‘even though’, means the result from the first clause would not happen in the second clause even if one presumes that the state or action in the first clause would happen.
● 힘들어도 최선을 다하세요. (Do your best even though it’s hard.)
● 제 아버지는 밥을 많이 먹어도 살이 안 쩌요. (My father doesn’t get fat even though he eats a lot.)
● 아무리 아파도 회사는 가야 해요. (I have to go to work no matter how much I’m sick.)
‘-은/ㄴ 적이 있다[없다]’ indicates a past experience being used with a verb. If someone haven’t had that experience, use ‘-은/ㄴ 적이 없다’.
● 저는 이 노래를 들은 적이 있어요. (I have listened to this song.)
● 제 친구는 중국어를 배운 적이 없어요. (My friend haven’t learned Chinese.)
● 한국 음식을 먹은 적이 있어요? (Have you ever eaten Korean food?)
‘-어하다/아하다/여하다’ is used to change an adjective to a verb. This grammar point can only be used with a third person subject. Unless the verbs ‘좋아하다’ or ‘싫어하다’ are used, which can be used in first person context.
● 그 소식을 듣고 마이클 씨가 슬퍼했어요. (Michael was sad when hearing about the news.)
● 엄마는 뱀을 무서워해요. (My mom feels scary of snakes.)