The particle -에 is the locative particle. -에 describes the static location of where a place or object exists (-에 있어요.) -에 also indicates the destination or goal when used with directional verbs such as 가다 or 오다. 집에 가요. (Go home.) But then there is -에서. This particle indicates the location of an action. 학교에서 공부해요. (Study at school.) With this particle, the -에 can be omitted, usually when following a vowel. 어디에서 공부해요? can be 어디서 공부해요? (Where do you study?) So -에 is a static location. Where something "is" or is going. -에서 (or -서) is where something "happens." Proper examples of "~에서" include: "오늘 학교에서 싸웠어" (Today I fought at school) "집에서 낮잠을 잤어요" (I took a nap at home) "어디에서 왔어요?" (Where did you come from?) "미국에서 왔어요." (I came from America) "중국에서 중국어를 배웠어요" (I learned Chinese in China) Proper examples of "~에" include: "지금 사무실에 있어" (I'm at the office right now) "내일 우리 집에 오세요 (Tomorrow, come over to my house) "어디에 갔다왔어?" (Where did you go [just now]/[on vacation]?) "호주에 갔다왔어" (I went to [and came back from] Australia) "어디에 살아요?" (Where do you live?) "한국에 살고있어" ([Right now] I live in Korea [but it's just temporary]) "어제 현대백화점에 갔어" (Yesterday, I went to [the] Hyundai Department Store) "책상위에 열쇠 있어" (The keys are on my desk) "창문 앞에 있어" (It's in front of the window) "서울에 사람이 많아" (There are a lot of people in Seoul) "지금 형이 집에 없다고?" (Did you say that your brother is not home right now?) "집에 가" (Go home) cf. "집에 왔어요" (I'm home [while talking on the phone to your wife]) "집에서 왔어요" (I am a citizen of a place "HOME"; lit. I come from home)

은/는 vs 이/가 are two different ways of saying things. 은/는 the topic marker says something organized around a concept, because that is a common way we view the world. On the other hand 이/가 the subject marker is about isolated, random things that are more difficult to categorize. Simply put, the two can be thought of as things (how something is) vs incidents (what happens). For example, here are sentences about a window. 1. 이 창문은 보기 좋다 = This window looks good. 2. 누가 돌을 던져서 이 창문이 깨졌어 = This window shattered because someone threw a rock. #1 talks about the window, keeping it as the topic. #2 relates an isolated fact, with the focus on the incident and not on the window. So 은/는 is commonly used for explaining things or introducing people (제 친구는 미국에서 왔어요), while 이/가 is often about random happenings (어제 밤에 큰 불이 났어요). 은/는 also has the side-effect of setting the noun apart from others, and 이/가 is someitmes used to identify an individulal out of a collection. - 이것(을) 내가 할게 = I'll do this one - no special nuance. - 이것은 내가 할게 = I'll do this one (but I don't know about the others) - 은 adds the nuance of "as for this". - 개는 다리가 네 개다 = Dogs have four legs (general statement about the dog as a species). - 개가 다리가 세 개네! = Why, the/this dog (I see) has only three legs (a comment on a specific dog with only three legs) And you're righit about 에 marking a location and 에서 indicating where something happens. Note that 에 can be used with action verbs too as long as the action just relates to it and does not start from there. 에서 always means the action starts at the place (but it may end anywhere). - 나는 일본에 갈 예정이다. Going somewhere originates from some other place, so 에 is correct and 에서 is wrong. - 이 사진은 일본에서 찍었다. Taking a picture is bound to the place, so only 에서 is correct. - 위험한 곳에 가지 마 = Don't go to a dangerous place. (에 indicates a destination) - 추운 방에서 기다렸다 = I waited in a cold room. (에서 indicates where the action took place)

I'll just answer this question in short, 은 and 는 are both called 'topic marking particles' (when added to the end of a noun, it marks that they are the topic of the sentence. 은 is used when the noun ends with a consonant and 는 is used when the noun ends in a vowel. 이 and 가 are both called 'subject marking particles'. 이 is used when the noun it is attached to ends in a consonant and 가 is used when the noun it is attached to ends with a vowel. 그리고 is a way of saying 'and', and this is a stand-alone word which can link different phrases. 에 is a time and location particle and when it is added to a noun, (for example, 집 meaning house) it could mean: 집에 - to the house, in the house (describes that you are not doing anything there), at the house, on the house 에서 is only a location particle and when it is added to a noun (집 again) it usually means that you are in the house (집에서) and that you are doing something there. It can also mean 'from the house'. For example: 집에 - in the house 집에서 - implies that you are doing something in the house that the action will later describe.

Quoted from http://www.learnkoreanlp.com/2011/12/subject-particles.html 는/은 and 가/이 both are used for the subject of a sentence but 는/은 introduces a topic or a subject whereas 가/이 identifies a subject. In addition to their differences already explored above, here is another big difference between the two particles. The topic particle, 는/은, is used in cases when we make a general or factual statement whereas 가/이 is not. For example, 치타는 빠르다 = Cheetah is fast 치타는 느리다 = Cheetah is slow (This would be a wrong statement) However, if you visited a zoo and saw a cheetah who seems to move very slowly, you might say, 치타가 느리다 = (That) cheetah is slow So the identifier particle, 가/이, indicates a certain person or thing that the speaker and listener know or are aware of. In this case, it would be that cheetah in the zoo. Here is another example, 바다는 푸르다 = The sea is blue 바다는 까맣다 = The sea is black (In general, this is a wrong statement.) But say, you saw the sea at night and you may exclaim, 바다가 까맣다! = The sea is black! The sea in this sentence is identified as a particular sea at night, and both the speaker and listener know which sea is being talked about. This is not a general statement. Therefore the identifier particle, 가/이, is used in this case. Of course, 바다가 푸르다 is also perfectly acceptable. However, the difference is that the sea in this sentence is also a particular sea that is known by both the speaker and the listener. 바다는 푸르다 = The sea is blue (A general statement) 바다가 푸르다 = The sea is blue (The sea is identified and known by the speaker and listener) It's similar to the way articles are used in English. For example, An apple is red = 사과는 빨갛다 (A general or factual statement about an apple) The apple is red = 사과가 빨갛다 (A particular apple that the speaker identifies and indicates to the listener)