Learn Hardcore Korean: i munjeneun gati iyagihamyeon geumbang haegyeolhal su isseo. - We can solve this problem quickly if we talk about it together.

는 marks the topic: 이 문제는 sets up “as for this problem,” and then the rest comments on it. The object of 해결하다 is understood from context (the topic), so it isn’t repeated.
You can also say 이 문제를 같이 이야기하면 금방 해결할 수 있어. Here, 이 문제를 is the object of 이야기하다 (“talk about this problem”), not the topic. Both are natural; 는 adds a slight contrastive feel (“this one, at least…”).

Who is the subject? There’s no “we.”

Korean often drops obvious subjects. Here, the subject is implicitly we/you and I (suggested by 같이, “together”). If you want to make it explicit, you can add 우리가: 우리가 같이 이야기하면…

What does the ending -면 in 이야기하면 mean exactly—“if” or “when”?

-면 expresses a condition and often maps to both “if” and “when/whenever,” depending on context.
Here it’s essentially “if/when we talk (about it) together.” If you want a pure “when (whenever),” you could use 이야기할 때(는), but -면 is very natural.

Can I use 함께 instead of 같이?

Yes. 같이 is common and casual; 함께 is a bit more formal/literary. Meaning is the same. Position it right before the verb phrase: 같이 이야기하면 or 함께 이야기하면 (not “이야기 같이 하면”).

Is 이야기하다 the best verb here? How is it different from 말하다, 의논하다, 상의하다, 토론하다?

이야기하다/얘기하다: to talk/chat/discuss (broad, everyday).
말하다: to say/speak (more about saying words; less “discuss together” vibe).
의논하다 / 상의하다: to consult/discuss to solve something (slightly more formal/problem-solving nuance).
토론하다: to debate/discuss pros and cons (often formal/academic). Here, 이야기하다 fits the friendly, cooperative tone.

What’s the difference between 이야기 and 얘기?

얘기 is the contracted form of 이야기. Both are standard; 얘기 feels a bit more colloquial. So 이야기하면 and 얘기하면 are both fine.

Does 금방 mean “soon” or “quickly”? I’ve seen both.

금방 is tricky: with future/context of possibility, it often means “in no time/quickly.” With past, it can mean “just now.”
- 금방 해결할 수 있어 ≈ “we can solve it quickly/in no time.”
- 금방 왔어요 ≈ “(I) just arrived.”
Related words:
- 곧: “soon” (time proximity).
- 바로/즉시: “right away/immediately.”
- 쉽게: “easily” (low difficulty, not speed).

Why 해결하다 and not 풀다 with 문제?

해결하다: to resolve an issue/situation/problem in life or work.
풀다: to solve a question/puzzle (tests, math problems). If “문제” here is a real-life issue, 해결하다 is right. If it’s an exam question, say 금방 풀 수 있어.

How does -(으)ㄹ 수 있다 work in 해결할 수 있어? Is it ability or possibility?

V-(으)ㄹ 수 있다 means “can/be able to,” covering both ability and possibility. Here: “can solve.”
Emphatic form: V-(으)ㄹ 수가 있다 (adds contrast or emphasis).
Negatives:
- V-(으)ㄹ 수 없다 = “cannot” (neutral).
- 못 V = “cannot” due to inability/obstacle (often stronger/immediate).

What politeness level is 있어 here? How do I make it polite or formal?

있어 is intimate/casual (반말).
Polite: 있어요 → 이 문제는 같이 이야기하면 금방 해결할 수 있어요.
Formal: 있습니다 → … 금방 해결할 수 있습니다.
Softer/more tentative: … 해결할 수 있을 거예요.

Can I say this with a passive, like “It will be resolved”?

Yes:

이 문제는 같이 이야기하면 금방 해결돼(요). (“gets resolved”)
… 금방 해결될 거예요. (“will be resolved”) Avoid overusing 될 수 있다 here; 해결될 수 있어 is grammatical but often sounds clunky. Prefer 해결돼(요)/해결될 거예요 for passive, or the original active 해결할 수 있어.

Can I move 금방 or other parts around?

Natural placements:
- 이 문제는 같이 이야기하면 금방 해결할 수 있어.
- 같이 이야기하면 이 문제는 금방 해결할 수 있어. (okay, shifts focus)
Keep 금방 near the predicate it modifies: 금방 해결할 수 있어.
Don’t split 같이 from its verb: use 같이 이야기하면, not “이야기 금방 같이 하면.”

Why are there spaces in 해결할 수 있어? I’ve seen people write 할수있어.

수 is a noun (“way/means”) in the grammar V-(으)ㄹ 수 있다, so it takes spaces: 해결할 수 있어.
No spaces: 할수있어 is a common typo.

Any pronunciation tips for this sentence?

같이 is pronounced like [가치] (t → ch sound).
할 수 often sounds like [할 쑤] (the ㅅ in 수 gets tensed in fast speech).
있어 is [이써].
Putting it together: you may hear something like [이 문제는 같이 이야기하면 금방 해결할 쑤 이써].

Does using 는 add a contrast, like “this problem (at least)…”?

Often yes. 이 문제는 can imply contrast or focus: “As for this problem (maybe unlike others), we can solve it quickly if we talk together.” If you don’t want that nuance, use 이 문제를 같이 이야기하면… or drop the demonstrative if context is clear.