How to Say "Or" in Japanese: か, または, and もしくは

Choosing the right Japanese word for "or" comes down to register. か is the casual, spoken "or" between nouns, または is the formal "or" of writing and notices, and もしくは is a more literary "or."¹ The choice matters: a written-register conjunction sounds stiff in conversation, while a casual particle would be out of place in a contract.

Overview: The Four Ways to Say "Or"

The Japanese "or" forms fall along a register-and-scope axis. The everyday particle か lives in speech; または and もしくは belong to writing and formal speech; and か repeated as 〜か〜か lays out two whole alternatives. Reference dictionaries gloss か, または, あるいは, and もしくは using one another, which is why learners often conflate them. The real difference is register and, in legal text, structural level, not core meaning.²³

A register-and-scope map

The table below places each form on its register and scope. The JLPT band reflects the consensus of recognized grammar references; there is no official JLPT vocabulary list published since the 2010 revision.⁴

Form	Kanji	What it does	Scope	Register	Band
か	(particle)	everyday "or" linking equal-rank items	nouns and clauses	casual / spoken	N4
〜か〜か	(particle)	か repeated to lay out two whole alternatives	clauses (often a yes/no pair)	casual / spoken	N4
または	又は	"select one of two or more similar things"	nouns and clauses	formal / written	N4
もしくは	若しくは	alternation "or," more literary	nouns and clauses	formal / literary	N3

か is classified as a coordinative particle (並助 / 並立助詞), a particle that links equal-rank words, when it expresses selection.¹⁵ または is the broad default of the formal set, while もしくは is the more restricted, literary alternant.⁴

もしくは sits a band above the others

Although this page treats もしくは as part of the N4 "or" toolkit, most reference lists place it around N3 because it is more formal and literary than または. The legal nesting hierarchy covered later is specialist register, outside the JLPT descriptors entirely.⁶⁴

"Or" disjunction vs. the か you already know

The particle か has several uses: the sentence-final question marker, the embedded 〜かどうか "whether or not," the indefinites 何か and 誰か, and the disjunctive "or" treated on this page. The "or" sense is a separate dictionary subentry. It is defined as listing several things and choosing one or some of them in the 「…か…か」 or 「…か…」 shape.¹

Position tells you which か you are seeing. When か sits between two equal-rank items (noun か noun, or clause か clause), it means "or." When it closes a sentence or comes before どうか, it is the question or embedded use.¹⁵

Tell the two か apart by what flanks it

Equal-rank item on each side means "or." A sentence boundary or どうか after it means a question. The disjunctive か never ends the utterance on its own.¹⁵

Form and Rules

か between nouns (casual "or")

The pattern is Noun + か + Noun, with an optional trailing か. コーヒーか紅茶 is the same as コーヒーか紅茶か, but the final か is commonly dropped in speech. The coordinative-particle sense is to list several things and choose one or some of them.¹

午後ごごからは雨あめか雪ゆきになるでしょう。¹
"From the afternoon it will probably turn to rain or snow."

The same particle also joins whole verbal clauses with this coordinative sense. That use leads into the 〜か〜か pattern below.¹ This is the everyday "or" of ordinary conversation.¹⁵

または: formal written "or"

The pattern is A または B, joining nouns or clauses. Dictionaries define it as a word used when selecting one of two or more similar things, and gloss it as a synonym of あるいは and もしくは.² In kanji it is written 又は and appears in official documents, statutes, instructions, and signage.²

ペン又またはボールペンで記入きにゅうのこと。²
"Fill this in with a pen or a ballpoint pen."

雪ゆき又またはみぞれでしょう。²
"It will probably be snow or sleet."

These instruction-and-forecast examples are the natural register for または: notices and announcements, not casual chat.²

もしくは: formal alternation "or"

The pattern is A もしくは B. Dictionaries define it as a word used to select one of two options, and gloss it against あるいは, さもなければ, and または.³ The 精選版 adds that it marks a relation where one of the surrounding items is selected, or where several items stand in parallel.⁶ In kanji it is 若しくは, and its register is formal and literary, frequent in legal text.³⁶

行いくか、もしくはやめるか。³
"Will you go, or else give it up?"

もしくは is the more bookish member of the pair. In everyday non-legal writing, where no nesting of "or" levels is needed, または is the safer default and is far more common.⁴

The 〜か〜か pattern across clauses

Here the particle か works at clause level in the same 「…か…か」 shape: Clause + か + alternative Clause + か. It lays out two whole alternatives, very often a yes/no pair such as 行くか行かないか. It still presents alternatives as "or." This is distinct from 〜かどうか "whether or not," which embeds a single yes/no question into a larger clause.¹⁵

Reference-grade attestations of the clause-level pattern carry a classical or literary flavor. The example below is early modern. A plain conversational 行くか行かないか could not be located verbatim in a reference source, so it is offered only as an illustrative shape, not a cited model.

けふかあすは戻もどられふ。⁵
"He will be back today or tomorrow."

The modern casual shape is illustrative only

A textbook-style 行くか行かないか、まだ決めていない ("I haven't decided whether to go or not") follows the same 〜か〜か pattern, but no reference-grade source attests that exact sentence. Treat it as an illustration of the shape rather than a sourced example.¹⁵

Nuance and Usage Contexts

Register: spoken か vs. written または / もしくは

か is the coordinative particle of ordinary speech.¹⁵ または and もしくは are conjunctions weighted toward written and formal registers: notices, forms, statutes, and manuals.²³

The practical rule is simple: in conversation, use か. Reserve または and もしくは for writing and announcements.²⁴

または vs. もしくは: the close pair

Dictionary glosses make または and もしくは mutual synonyms, so outside legal text they are usually interchangeable, with または the broad default.²³ もしくは is the more literary member. The selection-conjunction literature treats または as the unmarked default and もしくは and あるいは as more restricted alternants.³⁴

The clean default rule: if you are not writing legal text and do not need to nest two levels of "or," use または.⁴

The legal hierarchy: または as the larger division, もしくは the smaller

In statutory and legal Japanese (法令用語), the two forms split by structural level. When the choices have nested levels, the largest, outermost connection takes 又は and the smaller, inner connections take 若しくは.⁶⁷ The 精選版 states the distinction directly: equal-rank choices take 又は, but when there are large and small stages, the large takes 又は and the small takes 若しくは.⁶

The schema is the key rule. To express a two-level choice ((A・B)・C), write A若しくはB又はC. To express a three-level choice, only the single largest split uses 又は, and every finer split uses 若しくは.⁷ This nesting is tree-shaped, with one 又は at the top of the tree.

A verbatim statute shows the more common flat case. The items are all at the same level, and 又は alone connects the final pair of a comma-listed series.

種類しゅるい、品質ひんしつ又または数量すうりょうに関かんして契約けいやくの内容ないように適合てきごうしないものであるとき。⁸
"When it does not conform to the contract as to its kind, quality, or quantity."

In that statute, the items are flat: commas carry the earlier items, and 又は appears before the last one. This is the standard statutory listing pattern.⁸ This hierarchy is specialist, N3-plus register, not casual usage.⁶⁷

The nesting rule is specialist register

The 又は-over-若しくは hierarchy belongs to legal drafting, not everyday Japanese. Outside statutes and contracts, treat または and もしくは as interchangeable formal synonyms and do not try to nest them.⁶⁷

Inclusive vs. exclusive "or"

The Japanese disjunctive forms か, または, and もしくは are not formally marked for inclusive "and/or" versus exclusive "one but not both." The reading comes from context. This matches the broader cross-linguistic finding that natural-language disjunction stays ambiguous between the two readings, with even the most exclusive-seeming disjunctions remaining ambiguous.⁹

Formal logic separates inclusive ∨ from exclusive ⊻ as distinct operators. Everyday Japanese "or," like everyday English "or," leaves the distinction to context.⁹

Good to know

Don't reach for または in casual speech

または and もしくは are written and formal conjunctions, at home in notices, forms, and statutes. In casual speech, the natural "or" is the particle か, so choosing または in chat sounds stiff and announcement-like.²⁴ To ask which drink someone wants, コーヒーか紅茶、どっちにする？ sounds natural. コーヒーまたは紅茶、どちらにしますか would sound like a form being read aloud.²⁴

か is also a question marker, and context disambiguates

A learner can misread the disjunctive か as a question. The wrong parse of コーヒーか紅茶を飲む treats the first か as a question, yielding something like "Will I drink coffee? I drink tea." The correct reading is "I'll drink coffee or tea." Between two equal-rank nouns, か is the coordinative "or"; only a sentence-final か, or か before どうか, is the question use.¹⁵

"And" is a different toolset

The "or" set selects one alternative, so it cannot stand in for an "and" list. For combining nouns, Japanese uses と for exhaustive listing, や for non-exhaustive listing, or とか for casual listing. None of these are interchangeable with the "or" forms.¹ ペンかノートを持ってくる means "bring a pen or a notebook." To mean "a pen and a notebook," the sentence needs と, as in ペンとノートを持ってくる.⁵

Reading the kanji 又は and 若しくは

In official and legal text, these conjunctions frequently appear in kanji, 又は and 若しくは. Casual writing usually keeps them in hiragana as または and もしくは.²³⁸ もしくは traces to 漢文訓読, the kanbun-reading tradition, which is part of why it carries a formal, bookish tone.³

"または is the big bracket, もしくは is the small bracket"

In legal nesting, 又は marks the single outermost split and 若しくは marks the inner splits, so A若しくはB又はC reads as (A or B) or C.⁷ The mnemonic works because there is exactly one 又は, the big bracket, at the top level, and everything finer is 若しくは.⁶⁷

See also

• Japanese Conjunctions Overview: Clause-Linkers (接続助詞) vs. Sentence-Connectors (接続詞)
• The か Particle: Question Marker (and Disjunction)
• The と Particle: With, And, Quote
• The や Particle: Non-Exhaustive Listing "And"
• The とか Particle: Casual Non-Exhaustive Listing

References

Footnotes

1. 小学館.『デジタル大辞泉』, entry「か」(particle), 並助 (coordinative-particle) sense. Hosted at コトバンク. https://kotobank.jp/word/か-456254 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴

2. 小学館.『デジタル大辞泉』, entry「又は」(また‐は). Hosted at コトバンク. https://kotobank.jp/word/又は-634501 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹²

3. 小学館.『デジタル大辞泉』, entry「若しくは」(もしく‐は). Hosted at コトバンク (via Weblio). https://www.weblio.jp/content/もしくは ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

4. 中俣尚己「選択を表す接続詞「または」「あるいは」「もしくは」「ないし」「それとも」の使い分け」『實踐國文學』80巻, 2011, pp. 左52–左70. https://jissen.repo.nii.ac.jp/records/865 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

5. 小学館.『精選版 日本国語大辞典』, entry「か」(particle), 副助/並立助詞 sense. Hosted at コトバンク. https://kotobank.jp/word/か-456254 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰

6. 小学館.『精選版 日本国語大辞典』, entry「若しくは」(もしく‐は). Hosted at コトバンク. https://kotobank.jp/word/若しくは-646484 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

7. DOWAエコジャーナル「法文読解 基礎力養成講座 その1 ～又は・若しくは～」DOWAエコシステム株式会社. https://www.dowa-ecoj.jp/law/2019/20191201.html ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

8. 日本国 e-Gov 法令検索.『民法』(明治二十九年法律第八十九号) 第562条第1項. https://laws.e-gov.go.jp/law/129AC0000000089 ↩ ↩² ↩³

9. Nicolae, Andreea C., Aliona Petrenco, Anastasia Tsilia, and Paul Marty. "Do Languages Have Exclusive Disjunctions?" PMC, 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11666282/ ↩ ↩²