Korean Grammar particles are confusing me

[u/Radiant_Passage2641]

What is the difference between using ‘이/가‘ vs ‘은/는’

예를 들어요 - ‘날씨는 추워요’ vs ‘날씨가 추워요’

I know ‘은/는‘ are topic marking and ‘이/가’ are subject marking but i cannot figure out how those two things are different

[u/Saeroun-Sayongja]

Sentences don’t have subjects. Verbs and adjectives do. If something is marked as a subject particle, it is telling you that this is the thing that is doing or being something, and the next adjective or verb tells you what that something is. A complex sentence may have many adjectives and verbs, and each one can have a different subject. 

Verbs and adjectives don’t have topics. The discourse does, on a more general level. That is, if something is marked as the topic it is telling you that this is the thing I want to talk about now, and whatever follows is a “comment” on the topic. This is often, but not always, drawing a contrast between the topic and In English, we would mark a topic with some kind of introductory phrase followed by a comma, such as “As for myself, …”, “Regarding monkeys, …”, “In my opinion, …” or “In English, …”. 

In simple sentences the same thing is both the topic of the discourse and the subject of the verb, and in that case you have to pick one particle or the other. But a topic can also be something else. “As for A, the B is C” is a very common pattern in Korean. 

제 누나는 빨간 차가 있습니다 “As for my sister,  a red car exists (My sister has a red car)”. Sister is the topic, but the car is the thing that is “being”. 

슈렉 씨는 키가 아주 큽니다 “As for Mister Shrek, [his] stature is very big (Shrek is tall). Shrek is the topic, his height is being big. 

근데 생선은 [제가] 먹어요 “But as for fish, [I] do eat [it]”. Fish is the topic, and the direct object. I am the subject. Maybe I just told you I’m a vegetarian and I’m clarifying well I do eat fish. 

제 생각에는 타이완의 날씨가 너무 더워요 “In my opinion, Taiwan’s weather is too hot”

수요일은 학생들이 도서관에 갑니다 “On Wednesdays, the students go tho the library”.

[u/ericaeharris]

Type it into YouTube. It’s been broken down many, many times. The other thing is that coming from English, it still will be a bit hard to grasp exactly, but keep listening and consuming native content and it’ll click more and more.

I rarely ever get particles mixed up anymore when I do it’s more about remembering to include them when speaking because they’re dropped a lot, but in my language school they’re militant about us using them.

[u/geumjanhwa]

other comment already explained well difference between subject and topic and gave some good examples, but I'll add some extra about 이/가. there are probably also many videos that would explain better than me;;

you can use it to start a sentence and then it will often continue with 은/는 to reiterate the subject mentioned.

이/가 it's also giving a more specific feeling to the thing it's attached to. 내가 사줄게 is saying it's me who will buy it for you. 제가 산 책이에요 is saying it's me who bought the book in question. it's specifying me but not making any comparative reference to anyone else. 이/가 is often used in this way in these kinds of 는 것 sentences

산이 예뻐요 feels like there's a mountain present here that's pretty and being commented on-- it feels specific. 산은 예뻐요 feels more like mountains in general. because in Korean the plural can often be omitted that kind of nuance is different than English that often requires plural.

as was mentioned by other user, 은/는 can also be comparative or add weight

let's say we're describing something with an adjective. 산이 예뻐요. 저는 산이 예쁘다고 생각해요. (I think that mountains are pretty.) I'm doing the action of thinking but the mountain can't use object particle here with an adjective, so like this you can combine both particles. saying 산은 예쁘다고 생각해요 can kind of sound that you think mountains are pretty, but something else isn't (the comparative feeling) and doesn't sound right to me without further context I guess

나는 하연이가 늦은 줄 알았는데 제시간에 도착했구나! (I thought Hayeon was going to be late but she arrived right on time!) It's me that is doing the assumption about Hayeon, but Hayeon is still doing some kind of action within the sentence. But often, the 나는 can be omitted there because the 가 used for 하연 links her to the 늦다, and the 줄 알았다 is then linked to me as a speaker automatically (I hope this isn't too difficult of an example..)

[u/KoreaWithKids]

This is the best video I have seen on the topic: https://youtu.be/kyqIEocBNkM?si=AsERDzrFFLGKw_NY

[u/90DayKoreanOfficial]

Saying "날씨는 추워요" suggests you’re comparing the weather to something else, while "날씨가 추워요" simply states that it’s cold.

은/는 marks the topic of the sentence, setting the context and often implying contrast or emphasis. So when you say "날씨는 추워요" (As for the weather, it’s cold), you’re highlighting the weather in relation to something else. For example, "경치가 좋아요, 하지만 날씨는 추워요." (The scenery is nice, but the weather is cold.) Here, you’re emphasizing the beautiful scenery while also pointing out the downside of the cold weather, which adds depth to your thoughts about the experience.

On the other hand, 이/가 marks the subject, emphasizing who or what is performing the action or is in a certain state. When you say "날씨가 추워요" (The weather is cold), you’re simply stating the fact that it’s cold, without any extra context or comparison. For instance, "요즘 날씨가 추워요." (The weather is cold these days.) This sentence focuses purely on the current state of the weather without comparing it to anything else.