つまり / すなわち / 要するに: How to Say "In Other Words" in Japanese (Restatement and Summary)
つまり, すなわち, and 要するに are three sentence-initial connectives Japanese uses to reframe a point you have just made. They are the closest equivalents to English "in other words", "that is", and "in short".1 To choose among them, ask two quick questions: are you rewording the same idea or boiling it down to its gist, and how formal is the setting?
Overview
All three belong to the 換言（かんげん） family of connectives, whose job is paraphrase or restatement. They were the explicit subject of a foundational study by Ishiguro (2001), whose title translates as "On connectives expressing paraphrase, centering on sunawachi, tsumari, and yousuruni".1
A connective here means a 接続詞・接続表現, a connecting word or expression. It sits at the head of a sentence or clause and signals how it relates to what came before.
The two jobs: restate vs summarize
The split that organizes the topic is about purpose, not grammar. Two of these words reword; one condenses.
つまり and すなわち restate the same content in other words. The dictionary defines すなわち as "used when explaining again, in different words, something stated earlier; in other words; that is".2 In its adverbial sense, つまり is glossed "if one replaces it with other words; to put it differently; that is".3 Both definitions are built on 言い換え (rewording the same thing), and each dictionary entry names the other word as its synonym.32
要するに boils a longer point down to its gist. Its dictionary definition is "if one sums up what has been said so far; to put it briefly; in short".4 The key verbs are まとめる (sum up) and かいつまむ (condense to the gist). This is a reduction in volume, not a reworded restatement of equal length.
Hold one question in mind before using any of these words. If your second statement says the same thing at the same length, it is restatement, the territory of つまり and すなわち. If your second statement is shorter and selects only the essence, it is summary, the territory of 要するに.
Ishiguro (2001) frames the trio as expressing two paraphrase purposes. Sakurai (2022) restates this, noting that paraphrase by つまり either "explains the preceding portion concretely, or sums up its main point", and confirming that her data "conform to the two purposes of paraphrase pointed out by Ishiguro 2001".5
Where these sit among Japanese connectives
All three are sentence-initial connectives in the 換言 (paraphrase) relation. That is a different logical-relation family from addition (また, さらに) and from sequence or result (それで, そして).1 An addition connective adds new content, and a result connective moves the story forward. A paraphrase connective stays put and restates the point already on the table.
How each connective works
つまり: the everyday "in other words"
つまり is the most flexible of the three and a useful anchor for intermediate learners. Its core function is restatement: "if one replaces it with other words; to put it differently".3
The form is straightforward: a statement, a comma, つまり, then the reformulation.
地図の上方、つまり北方は山岳地帯である。3
"The top of the map, that is, the north, is mountainous terrain."
つまり also has a second, summarizing sense. The dictionary gives a separate adverbial gloss, "where the talk comes to rest; in short; in the end", so つまり can introduce a wrap-up as well as a reword.3 This overlap with 要するに and 結局 is why it stretches across so many situations.
今までいろいろ述べたが、つまりそれはこういうことになる。3
"I've said various things up to now, but in short it comes to this."
つまり is not a speech-only word. Both Ishiguro and Sakurai draw examples from the written BCCWJ corpus, confirming it works in writing as well as conversation.15
実家では甲斐犬、つまり、オオカミのような毛色と立ち耳が特徴的である中型の日本犬を飼っている。5
"At my parents' house we keep a Kai dog, that is, a medium-size Japanese breed marked by a wolf-like coat and pricked ears."
Both reference dictionaries gloss つまり plainly, with no literary (文語) tag. That places it comfortably in the casual-to-neutral range.3
すなわち: the formal "that is / namely"
すなわち does the same restatement job as つまり, but it is a step more formal. Its core definition is nearly identical: "used when explaining again, in different words, something stated earlier; in other words".2 What sets it apart is its formal, written, literary flavor, reinforced by its archaic kanji 即ち (also 則ち, 乃ち).26
It also has a distinct equation or identity sense. The dictionary gives a second gloss: "expresses that what was said before and what follows are exactly the same; precisely; truly".2 This is the "A, namely B" feel that suits definitions and numeric equivalence, where A and B are asserted to be identical.
日本の首都、すなわち東京。2
"Japan's capital, namely Tokyo."
生きることはすなわち戦いである。2
"To live is, precisely, to do battle."
Ishiguro (2001) is the academic basis for treating すなわち as the strict-equivalence member of the trio, the A=B relation. This contrasts with つまり's flexibility and 要するに's subjective summary.1
The literary pedigree is concrete. The 精選版 日本国語大辞典 cites すなわち from the 古今和歌集 (Kokin Wakashū), using the historical kana spelling すなはち.6
近き世に、その名聞えたる人は、すなはち僧正遍昭は、歌のさまはえたれども、まことすくなし。6
"Among those of recent times whose names are known, namely Bishop Henjō, the form of the poetry is accomplished, but it is wanting in sincerity."
要するに: "in short / to sum up"
要するに is the summarizer. Its definition, "if one sums up what has been said so far; to put it briefly; in short", turns on まとめる (sum up) and かいつまむ (condense to the gist). It encodes reduction to the essence rather than equal-length rewording.4
Ishiguro (2001) treats it as the subjective summary member of the trio: the second statement presents the speaker's own selection and condensation of the gist. This contrasts with すなわち's objective A=B.1 Sakurai (2022) likewise aligns it with the "summarize the main point" purpose.5
要するに勉強をしろということだ。4
"In short, it means: study."
The same condensing force can sting when you turn it on another person's words.
要するに君は何を言いたいのかね。4
"So in short, what is it you're trying to say?"
This is the "get to the point" use: a speaker condenses someone else's long explanation, which can read as impatient. The register guidance around that is in Good to know below.
Nuance and usage contexts
The register ladder: つまり ↔ すなわち
つまり and すなわち perform the same logical operation: they restate the same content. They differ chiefly in formality. The dictionaries cross-define them, glossing each with the other and with 言い換えれば (to put it another way), which confirms how close they are in meaning.32
The difference is register. つまり is the casual-to-neutral default, usable in both speech and writing. すなわち is the formal, written, literary-flavored step up, marked by its archaic kanji and classical attestation.26
The two sit on a single register ladder. When a sentence with つまり needs to climb into academic or legal writing, すなわち is usually the word it becomes.78
Restate vs summarize: つまり/すなわち vs 要するに
The other axis is the core contrast. つまり and すなわち keep the same propositional content, reworded. For すなわち, that reworking is a strict A=B.32 要するに reduces volume to the gist, "sums up" and "condenses".4
The two overlap in one real zone. Because つまり has that second sense glossed "in short; in the end", it can also wrap up, stepping onto 要するに's ground.3
A clean rule cuts through the overlap. If B is the same length as A, with the same content reworded, use つまり or すなわち. If B is shorter and selects A's essence, 要するに is the precise word. Ishiguro's distinction between subjective summary and equivalence is the academic backbone of that rule.1
Comparison at a glance
| Connective | Core job | Register | Typical setting | Rough English |
|---|---|---|---|---|
| つまり | Restate (same content, reworded); can also wrap up | Casual ↔ neutral | Speech, conversation, news, writing | "in other words", "that is", "in short" |
| すなわち (即ち) | Restate / equate (A = B; definitions) | Formal / written, literary | Academic, legal, formal writing | "namely", "that is", "i.e." |
| 要するに | Summarize (condense to the gist) | Spoken and semi-formal | Speech, speeches, semi-formal writing | "in short", "to sum up", "the point is" |
The table cells are sourced as follows: つまり,3 すなわち,26 要するに,4 with the register split also reflected in Bunpro's level tags.789
There is no official JLPT vocabulary or grammar list, so every level tag is a third-party reconstruction, and sources disagree. Bunpro places つまり at N3 and 要するに at N2. すなわち is tagged N3 by Bunpro but pushed toward N2 by other resources. Treat this article's N3 framing as anchored on つまり, with すなわち and 要するに as a level step up rather than fixed numbers.789
Good to know
つまり as a spoken filler and the listener's "つまり…？"
In conversation, つまり also serves two roles that go beyond clean written restatement. A speaker may use it as a thinking pause while gathering a wrap-up. A listener may use a rising "つまり…？" to ask the other person to condense what they have just said. The dictionary's second adverbial sense, "where the talk comes to rest", supports つまり introducing a speaker's own wrap-up.3 These spoken uses are real, but they are described here rather than illustrated, because no reference-grade verbatim example of the filler use or the listener prompt was available to cite.
Why 要するに can sound rude
Using 要するに to recast someone else's long explanation can come across as condescending. A manners feature from Oggi (小学館) observes that it "carries a condescending nuance, risking a cheeky impression of 'let me explain this simply for you'", and that interrupting others with it "tends to invite dislike".10 This is register guidance from an etiquette piece rather than a hard linguistic rule, but the caution is worth heeding.
The safer pattern is to summarize your own point with 要するに, not the other person's. The dictionary's own example 「要するに君は何を言いたいのかね」 ("So in short, what are you trying to say?") is itself the blunt "get to the point" use, which shows why the word can sting.4
Kanji and etymology behind the three words
つまり derives from 詰まる (to be packed or condensed). The dictionary headword 「詰り（つまり）」 confirms that kanji base, though the connective is almost always written in kana.3
すなわち is written 即ち, 則ち, or 乃ち, all with an archaic feel. The headword and the classical 古今和歌集 (Kokin Wakashū) attestation, with its historical kana すなはち, mark its literary pedigree.26
要するに comes from 要する (to require, or to boil down to the essential 要, "the point"). The headword 「要するに」 and the まとめる / かいつまむ glosses tie it directly to extracting the 要点, the main point.4
結局 and 言い換えれば: neighbors that are not restatement
結局（けっきょく） marks an outcome, not a restatement. The dictionary defines it as "a word expressing how things settle at the final point after various twists and turns", with synonyms つまるところ and とどのつまり.11 It is an end-result marker ("in the end", "after all"), distinct from rewording. The boundary is easy to blur because つまり's second sense lists 結局, so the safe habit is to keep 結局 for outcomes and つまり/すなわち/要するに for paraphrase.3
言い換えれば / 言い換えると ("to put it differently") is the plain verbal paraphrase phrase, and both すなわち and つまり are glossed with it in the dictionaries.32 It is the literal phrasal equivalent of the restatement job. As a transparent form of 言い換える, it is useful to recognize as a longhand stand-in for つまり.
See also
- Japanese Conjunctions Overview: Clause-Linkers (接続助詞) vs. Sentence-Connectors (接続詞)
- また / さらに / その上: How to Say "Furthermore" and "On Top of That" in Japanese
- そして / それで / それから: Narrative, Result, and Sequence in Japanese
- でも / しかし: Sentence-Initial "But" and "However" in Japanese
- ただし / もっとも: How to Add a Proviso or Qualification in Japanese
- How to Say "Or" in Japanese: か, または, and もしくは