Learn Hardcore Korean: siktak wie jageun mulgeondeuri manhaseo jeongrihaeya haeyo. - There are so many small items on the table that I need to organize them.

In Korean, to express a static location (“on/at”), you attach the location particle 에 to a place noun. 위 by itself just means “top” or “surface.” Adding 에 turns it into “on top of.” So 식탁 위에 literally means “on the dining table.” Without 에, it wouldn’t mark the place where things exist.

What’s the difference between the particles -에 and -에서 when talking about location?

Use -에 for stating where something is or exists (“at/on”). Use -에서 when you describe where an action takes place or when you talk about the starting point of movement: • 식탁 위에 작은 물건이 있어요. (Static existence: there are things on the table.)
• 식탁 위에서 밥을 먹어요. (Action location: I eat on the table.)
In our sentence, we’re describing where the objects are, so 에 is correct.

Why is -들 used in 물건들이? Is it necessary?

The suffix -들 marks plurality (“items” rather than “item”). It’s optional in Korean because context often makes number clear.
• With 들: 작은 물건들이 많아서… (emphasizes “many small items”)
• Without 들: 작은 물건이 많아서… (still understood as “many small things”)
Adding 들 simply clarifies that you’re talking about multiple objects.

Why isn’t there a subject particle 이/가 after 물건들?

Korean frequently drops case particles when the meaning is obvious. Here, 물건들 already functions as the subject of 많아서, and adding -이/가 (→ 물건들이+가) is grammatically fine but often omitted in casual speech. The plural marker -들 plus context makes the subject role clear without -이/가.

What does -아서 do in 많아서?

-아서/어서 is a connective ending that links two clauses by showing cause or reason. In 많아서, it means “because (there are) many.” So the first clause explains why the second clause occurs:
“Because there are many small items on the table, I need to tidy up.”

What does the construction -아/어야 하다 express in 정리해야 해요?

-아/어야 하다 expresses necessity or obligation (“have to/need to”).
• 정리하다 = “to tidy up.”
• 정리해야 하다 = “to have to tidy up.”
Adding -요 for politeness gives 정리해야 해요, meaning “I have to tidy up.”

Could we use 정리해야 돼요 instead? Is there any difference from 정리해야 해요?

In everyday Korean, 해야 돼요 and 해야 해요 both mean “have to do.” They’re interchangeable in most contexts.
• 해야 돼요 can feel like an external requirement or rule.
• 해야 해요 might feel more like your own decision or plan.
In practice, native speakers use them almost identically.

Why is the subject omitted in the sentence? Who needs to tidy up?

Korean often omits subjects when they’re clear from context. Here, the implied subject is 저(가) (“I”). You could say 제가 정리해야 해요, but dropping 제가 is more natural once the speaker’s role is understood.