Japanese Pseudo-Cleft Sentences (～のは...だ): How to Put One Element in Focus

Japanese pseudo-cleft sentences use the ～のは...だ pattern to lift one element out of a sentence and spotlight it as the focus. The rest of the sentence stays in the background as already-known information.¹² For an N3 learner, this construction turns a flat statement into a pointed answer to "which one?", "who?", or "why?".

Overview

In Japanese linguistic terminology, the ～のは...だ construction is a 分裂文 (bunretsu-bun, "cleft sentence"). In school grammar, it is a 強調構文 (kyōchō-kōbun, "emphasis construction").¹² Source ¹ states the equivalence directly: 「分裂文（cleft sentence）とは，学校文法等で強調構文と呼ばれる構文である。」¹

More precisely, ～のは...だ is the pseudo-cleft (擬似分裂文) type. Its shape is 「subordinate clause + copula + X」. This contrasts with the true cleft shape, 「it + copula + X + subordinate clause」.²

What "cleft" means: splitting one sentence into presupposition + focus

A cleft splits one ordinary sentence into two parts. Japanese Wikipedia defines it as 「単文の中のある成分を強調するために抜き出し、コピュラ文を主節とする複文に変換した形の文」. In other words, it is a complex sentence formed by extracting one component from a simple sentence to emphasize it, with a copula sentence as the main clause.²

The two parts have names. The ～の part is the presupposition, the information already taken as known. The part before だ is the focus, the new information being singled out. Source ³ treats the focused element as what the construction brings to 焦点 (the focus position) and explains that 強調 here means moving an element into that focus slot.³

In the words of source ¹, citing 高見 1999, the focus is 「話し手が最も伝達したい部分」, the part the speaker most wants to convey. Source ¹ adds that the cleft is 「焦点が文のどの要素であるかを示すことができる構文」, a construction that can show which element of the sentence carries that focus.¹⁴

The structure is easiest to see as a split. The diagram below maps a plain statement onto its two cleft halves.

The canonical pair from the academic literature shows this in action.¹⁴

太郎たろうが最近さいきん興味きょうみを持もっているのは、パソコン通信つうしんだ。¹⁴
"What Taro has recently taken an interest in is computer networking."

A real broadcast cleft, attributed by source ¹ to NHK 「おはよう日本」, focuses on a school against the field of all the others.¹

4081チームの頂点ちょうてんに立たったのは、佐賀北高校さがきたこうこうでした。¹
"The one that stood at the top of 4,081 teams was Saga-Kita High School."

のは = の nominalizer + topic は

のは has two pieces: the nominalizer の plus the topic particle は. の packages the preceding clause into a single noun-like unit. は makes that unit the topic of the sentence.⁵

This article assumes you have already met both pieces and does not re-teach them. What matters here is the work they do together: they turn the presupposition clause into a topic that something is then asserted about.

読よむのは私わたしです。⁵
"I am the one who reads."

君きみを愛あいするのは、私わたしだ。⁵
"I am the one who loves you."

Where this sits at JLPT N3

The cleft construction proper is pitched at N3 by the dedicated teaching sources.⁶⁷ Learners meet the raw building blocks earlier: の-nominalization and のは appear around N5–N4.⁵ What comes in at N3 is the focus construction itself, with its presupposition-and-focus split, its tense alternations, and the のは-versus-のが choice.⁶⁷

The pieces come earlier than the pattern

You likely already use のは to nominalize and topicalize from earlier study. The N3 step is learning to read and build it as a deliberate focus device, not just as "the act of doing X."⁵⁷

The construction is register-neutral. Source ¹ documents heavy use in NHK and TBS news broadcasts, a formal spoken register.¹ Teaching sources also present it for everyday answering and correcting.⁷⁸ The politeness comes entirely from the copula: だ, です, or でした.

Form: building ～のは...だ

From a plain sentence to a cleft: move the focused element to the だ slot

The mechanics are a three-step rewrite. Take a plain sentence and decide which element to spotlight. Move that element to the slot after だ. The remainder becomes a plain-form clause closed by の, then topicalized with は.⁸

Source ⁸ flags one case-marking shift in this rewrite: the original topic は on 田中さん becomes the subject が inside the presupposition clause (田中さんが…).⁸

田中たなかさんが先月せんげつ行いったのはハワイです。⁸
"Where Tanaka went last month was Hawaii."

Aさんが生うまれたのは大阪おおさかです。⁸
"Where A was born is Osaka."

The presupposition clause is a noun-modifying clause

The string before のは is a noun-modifying (relative) clause whose head is the nominalizer の.² It follows the same rules as any noun-modifying clause, including taking a plain (普通形) predicate before の.⁵⁷ This article does not re-cover those rules. It assumes the noun-modifying clause as a given and builds the focus reading on top of it.

The key detail is how the final predicate before の inflects. The surface form changes with the part of speech and tense, as shown next.

The なのは / たのは / かったのは alternations

The predicate that feeds の inflects by part of speech and tense. The table collects the four patterns.

Predicate type	Before の	Example
Verb, present	dictionary form + のは	行くのは, 読むのは5
Verb, past	plain past + のは	行ったのは, 決きめたのは98
Noun / な-adjective	な + のは	独身どくしんなのは, 静しずかなのは97
い-adjective, present	plain form + のは	高たかいのは, 楽たのしいのは7
い-adjective, past	かった + のは	楽しかったのは7

Source ⁹ gives the formation set verbatim as: Verb (casual) + のは; Noun + なのは; な-adjective + なのは; い-adjective + のは.⁹

The key point in the noun and な-adjective row is な. A noun or な-adjective predicate takes the prenominal copula form な (formal: である) before の, never plain だ.⁹

A noun predicate with な, where だけ adds exhaustive focus:

このメンバーの中なかに独身どくしんなのは田中たなかさんだけです。⁹
"Among these members, the only one who is single is Tanaka."

A な-adjective predicate with な:

大切たいせつなのは、慌あわてないことです。⁷
"What is important is not to panic."

An い-adjective in its past かった form:

楽たのしかったのは、学校がっこうの遠足えんそくです。⁷
"What was fun was the school excursion."

For a past verb before たのは, source ⁹ prints the following reason-focus sentence. It has both an outer topic 私たちは and the inner …のは, which is slightly redundant. Read it as an attestation of the たのは inflection rather than as a model of clean style.⁹

私わたしたちは結婚けっこんを決きめたのは子こどもができたからです。⁹
"The reason we decided to get married is that we were going to have a child."

A cleaner past-verb cleft, with the focus on a reason clause, appears under the focus slot below.³

What goes in the focus slot

People, things, times, places, reasons

The element after だ/です can be a person, a thing, a place, a time, or a whole reason clause. In each case, the focus keeps the semantic role it had in the base sentence. However, the case particle it would have carried is normally dropped before the copula.

A place appears bare, as in 大阪です and ハワイです, with no に.⁸ A person appears as 佐賀北高校でした, 田中さんだけです, or 私だ.¹⁹⁵

A time focus:

やっと駅えきに着ついたのは、もう列車れっしゃが出でたあとだった。³
"It was after the train had already left that we finally reached the station."

A reason focus, where the whole から-clause is the focus:

おいしいのは、スパイスを利きかせたからだ。³
"The reason it tastes good is that we used plenty of spice."

For the reason type, the case-particle question does not arise, because から already heads the focus.³

のは vs のが: topic-focus vs neutral/exhaustive

Both のは and のが can attach to the same cleft, and the choice shifts the framing. Source ³ (庭三郎) draws the contrast directly. With ～のは, the sentence is a 主題文 (topic sentence), and the ～の part is its 主題 (topic). Use it when something is already at issue and the rest of the sentence comments on it. With ～のが, the ～の part is not a topic (主題ではありません). The whole sentence then reads as newly introduced, closer to a presentational statement, with the focus resting on the 「Ｎだ」 part.³

This difference is genuinely hard to feel as a learner. Source ³ itself calls explaining it 「かなり難しい」 (quite difficult).³ A workable first approximation: reach for のは when you are answering a question already in the air. Notice のが in sentences that present a whole new situation at once.

Source ² shows both particles on one cleft, marking the choice as available.

花瓶かびんを割わったのは（が）あいつだ。²
"The one who broke the vase is that guy."

Nuance and usage contexts

Correcting, contrasting, and answering "which one?"

The cleft singles out one element against its alternatives. That makes it a natural shape for corrections and emphatic answers. Source ⁷ describes it as 「何かを聞かれて、強調して答えたいときによく使う」: often used when you are asked something and want to answer with emphasis.⁷

Source ⁸ presents it as a way to correct a false assumption. Asked 「Aさんは東京で生まれましたか？」(Was A born in Tokyo?), a speaker corrects the place with 「Aさんが生まれたのは大阪です」(Where A was born is Osaka).⁸

The contrast can be made explicit, layering ではなく or の方だ onto the cleft.⁶

私わたしが言いいたいのは、この方法ほうほうでは無理むりだということです。⁷
"What I want to say is that this method won't work."

わたしが怖こわいのは、犬いぬではなく飼かい主ぬしの方ほうだ。⁶
"What I'm afraid of is not the dog but its owner."

Contrast with the English it-cleft and wh-cleft

English has two clefts, and Japanese ～のは...だ lines up more neatly with one than the other. Source ¹ sets all three side by side: the it-cleft 「It was perfume that Mary bought in France.」, the wh-cleft 「What Mary bought in France was perfume.」, and the Japanese 「太郎が最近興味を持っているのは、パソコン通信だ。」¹⁴

The structural twin is the wh-cleft ("What… is X"), which matches the schema 「subordinate clause + copula + X」.² The English it-cleft ("It is X that…") is only a looser equivalent.

Why "it is X that" is an approximation, not a translation

English it-clefts open with a dummy "it" that carries no meaning. Japanese has no such dummy. It clefts the presupposition itself and marks it as the topic with は. So 「太郎が…のは」 corresponds to the English "What Taro…" far more closely than to the dummy-"it" frame.²

Good to know

Don't double-mark: drop the focused element's case particle before だ

When a place, time, or other role-bearing noun moves into the focus slot, the case particle it carried in the plain sentence does not come with it. A learner who keeps the locative に and writes a constructed ～のは京都にだ is over-marking. The focus noun stands bare as the complement of the copula, so the natural form is ～のは京都だ. This matches the sourced examples, where a place appears as plain 大阪です and ハワイです with no に.⁸

The contrast, with a constructed place noun to show the pattern:

正しくない: ～のは京都きょうとにだ。
正しい: ～のは京都きょうとだ。
"…is Kyoto." (the locative に does not survive before だ)

The role the noun played is recoverable from the presupposition clause, so the bare noun is unambiguous. This is an observation drawn from the sourced examples (⁸) rather than an explicitly stated prescriptive rule. Treat it as a reliable pattern rather than a quoted edict.

なのは, not だのは: the copula before の

After a noun or な-adjective, the predicate takes the prenominal copula な (or formal である) before の, never plain だ. The form 独身だのは is wrong. The correct shape is 独身なのは. Source ⁹ lists the formation explicitly as "Noun + なのは" and "な-adjective + なのは."⁹

独身どくしんなのは田中たなかさんだけです。⁹
"The only one who is single is Tanaka."

のは...だ overlaps with but is not のだ/んだ

The cleft is easy to confuse with the explanatory のだ/んだ, because both put の after a clause. Source ² shows the two side by side. The cleft 「花瓶を割ったのは誰だ？」asks "who is it that broke the vase?", with a presupposition clause and a focus on 誰. The explanatory 「誰が花瓶を割ったのだ？」is a full plain sentence closed by sentence-final のだ, asking for an explanation.²

The parse differs. In the cleft, の is the nominalizer and は topicalizes the presupposition, leaving a focus slot after だ.

In のだ, の attaches to a whole sentence, and だ simply closes it. There is no separate focus slot. The two forms look alike on the surface but split apart underneath.

A note on こそ and other focus devices

Clefting is not the only way Japanese marks focus. Particles such as こそ and だけ also single an element out. They do so lexically, by attaching to a phrase, rather than syntactically, by splitting the sentence in two. The sourced data shows だけ riding on a cleft to mark exhaustive focus, as in 「独身なのは田中さんだけです」(the only one… is Tanaka).⁹ The こそ comparison is a general one here. A dedicated treatment of these focus particles is left for separate coverage.

See also

• Japanese Subordinate Clauses: How Embedded Clauses Work (Relative, Complement, Quotation, Embedded Question)
• The の Particle: Possessive, Nominalizer, Attributive
• Japanese Complement Clauses with こと: The Abstract Nominalizer for Sentences-as-Nouns
• Japanese ～という (to iu): Naming, Defining, and "the Fact That"
• Japanese Word Order: SOV and the Head-Final Principle
• Japanese Focus Prosody: Pitch Widening, Contrastive は, and Information Structure

References

Footnotes

1. 轟里香 (Todoroki, Rika). 「日英語における強調表現」(On Emphatic Expressions in Japanese and English). 北陸大学紀要 第33号 (Bulletin of Hokuriku University, No. 33), pp. 101–110. https://www.hokuriku-u.ac.jp/library/libraryDATA/kiyo33/kyou3.pdf ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷

2. ウィキペディア日本語版 (Japanese Wikipedia). 「分裂文」(Cleft sentence). https://ja.wikipedia.org/wiki/%E5%88%86%E8%A3%82%E6%96%87 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹

3. 庭三郎 (Niwa, Saburō). 「57. 名詞節(2)」, 『現代日本語文法概説』(A General Survey of Modern Japanese Grammar), section 57.5 強調構文. https://niwasaburoo.amebaownd.com/posts/5773549 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰

4. 高見健一 (Takami, Ken-ichi). 『機能的構文論による日英語比較』. くろしお出版 (Kurosio Publishers), 1999, p. 146. (Cited within and through ¹.) ↩ ↩² ↩³ ↩⁴

5. Bunpro. "の (JLPT N5)" [のは nominalizer + topic]. https://bunpro.jp/grammar_points/%E3%81%AE%E3%81%AF ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

6. Bunpro. "のはXの方だ (JLPT N3)." https://bunpro.jp/grammar_points/%E3%81%AE%E3%81%AFx%E3%81%AE%E6%96%B9%E3%81%A0 ↩ ↩² ↩³ ↩⁴

7. 日本語あれこれ (Nihongo Arekore). 「中級へ行こうの教え方（～のは）【強調構文】 JLPT N3の文法の解説と教え方」. https://nihongo-arekore.com/n3-14/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³

8. にほんご部 (Nihongobu). 「【文法６】みんなの日本語初級第３８課 ～のは～です（強調構文）」. https://nihongobu.net/nominaliser-emphasize/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹²

9. JLPT Sensei. "JLPT N4 Grammar: のは〜だ (nowa~da) Meaning." https://jlptsensei.com/learn-japanese-grammar/%E3%81%AE%E3%81%AF%E3%80%9C%E3%81%A0-nowa-da-meaning/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴