The particle -에 is a very important particle that can appear multiple times in one sentence. It’s main uses are to indicate the time and to indicate the place where you are going to.
The first use for the particle -에 is to indicate the place where you are going to. Therefore, this use only appears with verbs that imply a movement such as 가다 (to go), 오다 (to come), 다니다 (to attend, to commute), 아가다 (to return), 도착하다 (to arrive), etc. Do not mix the particle -에 up with the particle -에서. They are highly similar, but the latter indicates where an action takes place, the former where one is moving towards.
-에 is also the particle when you use the words 있다 or 없다. It then indicates the location where something is/exists.
가: 쇼핑을 하러 백화점에 갈래요?
나: 미안해요. 지금은 시간이 없어요. 내일 갈래요?
A: Do you want to go to the department store for shopping?
B: I’m sorry. I don’t have time right now. Do you want to go tomorrow?
Another use for -에 is to indicate the time when an action or event takes place. It naturally attaches itself to nouns that express a time like 시 (hour), 일 (day), etc. However, you cannot attach the particle to some words that indicate time. Among the words that do not use -에 are: 그제 (day before yesterday), 어제 (yesterday), 오늘 (today), 내일 (tomorrow), 모레 (day after tomorrow), 언제 (when), etc.
가: 언제 운동을 보통 해요?
나: 토요일에 운동을 보통 해요.
A: When do you usually exercise?
B: I usually exercise on Saturday.
In our -에게 and -한테 article, we also discussed that the particle -에. You use it also to indicate the indirect particle in a sentence for non-sentient living creatures (like plants) and inanimate objects. Read that article for a more in-depth discussion on the indirect object in Korean.
How To Use
Using the particle -에 is, like many other Korean particles, very simple. It follows the ‘no rule’ Korean grammar rule, meaning you don’t have to worry over things like consonants or vowels. You simply attach the particle to the noun and you are done.
There is one small thing you need to remember when it comes to -에. The time indicating -에 can only appear once in a sentence. Therefore, you attach it to the last noun representing time in the sentence, not to each individual time noun.
일요일 열두 시 반에 점심을 먹으러 맛집에 가기로 했어요. (-에 is attached to the final time noun in the sentence 반.)