그러니까 · 그러므로 · 따라서: Therefore / Thus

Korean has a plain word for "so" — 그래서 — but it also has a small family of conjunctions that mean specifically therefore: they present the previous sentence as the reason and the next as the conclusion drawn from it. The three that matter are 그러니까 (spoken, "so / therefore, as I figure it"), 그러므로 (formal, logical "therefore"), and 따라서 (the "thus / accordingly" of academic argument). They look interchangeable in a dictionary, but they live in different registers and — in one crucial case — do a job 그래서 grammatically cannot.

From a clause connective to a sentence conjunction

Two of these three are built from the demonstrative verb 그렇다 ("to be so / to be that way") plus a connective ending. 그러니까 = 그렇다 + -(으)니까, the "because / since" ending. So 그러니까 literally means "because it is so → therefore." 그러므로 = 그렇다 + -(으)므로, the formal written "because." The connective ending normally glues two clauses inside one sentence (비가 오니까 우산을 챙겨요, "since it's raining, grab an umbrella"), but when you promote it to sentence-initial position on top of 그렇- , it becomes a standalone conjunction that reaches back across a full stop.

따라서 is the odd one out: it is not from 그렇다. It comes from 따르다 ("to follow") + -아서, so it literally means "following from that." That etymology is worth holding onto — 따라서 is the conjunction of logical entailment, the "it follows that" of formal reasoning.

그러니까: reasoning you stand behind

그러니까 (informal–neutral; spoken and casual writing) is "so / therefore" delivered as the speaker's own reasoning. Where 그래서 just reports a cause neutrally, 그러니까 says "given that, the way I see it, this follows" — it foregrounds you as the one drawing the inference.

The killer feature: 그러니까 can precede a command

Here is the fact that decides everything. 그래서 cannot stand in front of an imperative, a request, or a suggestion — but 그러니까 can. Because 그러니까 frames the first sentence as grounds for acting, it licenses a following order (-(으)세요), a request, or a "let's" proposal. 그래서, which merely reports a resulting event, does not.

Try to swap in 그래서 before those imperatives and a Korean ear rejects it. This single restriction is the number-one reason to keep 그러니까 in your active vocabulary from early on: any time your conclusion is an instruction, a plea, or a proposal, 그러니까 is the correct bridge.

그니까 / 그니깐: the spoken contraction that became a filler

In real speech 그러니까 almost always contracts to 그니까 — and often 그니깐 with an extra ㄴ (both informal/spoken only; never write them in formal text). What makes 그니까 special is that it has drifted beyond "therefore" into a conversational filler meaning roughly "I mean… / like I said…" or, as a full-throated agreement, "exactly, right?!"

The agreement 그니까(요) works because you are saying "because [what you said is true] — yes." You are affirming the other person's premise so hard that the "therefore" collapses into a "totally." When you hear a Korean speaker sprinkle 그니까 through a story, they are not always concluding anything — they are stalling, re-anchoring, and signalling "I'm on the same page."

그러므로: the formal, logical "therefore"

그러므로 (formal; written and academic) is the buttoned-up cousin. It states a logical consequence and belongs in essays, legal text, formal speeches, and reasoning laid out step by step. It never precedes a command; it links a premise to a proposition. Because it is written register, examples naturally appear in the plain 한다체 (written declarative) rather than 해요체.

따라서: "thus / accordingly" in argument and academic prose

따라서 (formal; academic and expository) is the workhorse "thus" of papers, reports, editorials, and any writing that walks a reader through evidence to a conclusion. It signals entailment: from the foregoing, it follows that. Of the three, it is the most neutral and the most common in serious prose — you will meet it constantly in Korean newspapers and academic articles.

The reframe: neutral cause vs. "given this, it follows"

English collapses all of this into "so" or "therefore," which is why learners reach for 그래서 by default and sound flat. Hold the distinction like this:

Common Mistakes

1. Using 그래서 in front of a command. This is the most frequent error, because English "so" happily precedes an imperative ("It's dangerous, so be careful"). Korean 그래서 does not.

2. Dropping formal 그러므로 / 따라서 into casual speech. They are written-register conjunctions; in chat they sound robotic.

3. Writing the contraction 그니까 in formal text. 그니까/그니깐 are spoken only. In an essay you need 그러므로 or 따라서.

4. Splitting the clause ending -(으)니까 into a new sentence. -(으)니까 attaches to a verb stem inside one sentence; only 그러니까 stands alone. Don't write 오니까 as its own sentence.

Key Takeaways

• 그러니까 = spoken reasoning "so / therefore," and the only one of the family that can precede a command, request, or suggestion — 그래서 cannot.
• 그니까 / 그니깐 are its everyday contractions, doubling as the filler "I mean… / exactly."
• 그러므로 is the formal, logical "therefore" of written and legal prose; 따라서 ("thus / accordingly") is the "it follows that" of academic argument, and comes from 따르다 ("to follow"), not 그렇다.
• Match the conjunction to the register, and remember the imperative test — it is the one hard rule that separates 그러니까 from all the rest.