JLPT N1Written, formal

か否いなかwhether or not (written)

The written かどうか. 否いな is "not so", read いな here, so it says "whether it is so or not". Reports, legal and academic writing and newspapers use it. Out loud people say かどうか.

新しん制せい度どを導どう入にゅうするか否いなかは、費ひ用よう対たい効こう果かの分ぶん析せき後ごに決けっ定ていする。

Whether to introduce the new system will be decided after a cost-effectiveness analysis.

How to form it

Plain form + か否いなか

A noun or な-adjective usually takes である: 違い法ほうであるか否いなか. Straight after a noun is found too: 会かい員いんか否いなか. The particle after it is usually written out: か否いなかを, か否いなかは, か否いなかによって.

Before it: A yes-or-no matter: 承しょう認にんする, 適てき用ようされる, 適てき切せつである.
After it: Mostly deciding, checking or asking: 判はん断だんする, 検けん討とうする, 確かく認にんする, 問とう.
Where you'll meet it: Reports, papers, contracts, court rulings, newspapers, exam passages. Out loud mostly in presentations and debates.
In everyday speech: かどうか, which is also fine in most writing.

In use

実じっ験けん条じょう件けんが適てき切せつであるか否いなかを、審しん査さ委い員いん会かいが確かく認にんした。

The review committee checked whether the experimental conditions were appropriate.

調ちょう査さを継けい続ぞくするか否いなかについて、専せん門もん家かの意い見けんを求もとめた。

Experts were asked for their views on whether to continue the investigation.

この規き定ていが適てき用ようされるか否いなかは、契けい約やく締てい結けつ日びによって決きまる。

Whether this provision applies depends on the date the contract was concluded.

The same as かどうか, in formal dress

委い員いん会かいは計けい画かくを承しょう認にんするか否いなかを来らい月げつ判はん断だんする。

The committee will decide next month whether to approve the plan.

A report.

計けい画かくを承しょう認にんするかどうかは、来らい月げつ決きめます。

We will decide next month whether to approve the plan.

A committee member, telling you.

The meaning is the same. The words around it change with it: 判はん断だんする in the report, 決きめます out loud.

Said to a friend, it sounds like a ruling being read out.

Sounds odd: 飲のみ会かいに行いくか否いなか、まだ決きめてない。

I haven't decided yet whether I'm going for drinks.

行いくかどうか.

Close neighbours

かどうかN4

The everyday "whether", in conversation and in ordinary writing.

田た中なかさんが会かい議ぎに参さん加かするかどうか、まだ分わかりません。

I still don't know whether Mr. Tanaka is coming to the meeting.

や否やN1

The same 否いな, another meaning: the moment one thing happens, the next follows.

電でん車しゃが駅えきに着つくや否いなや、待まっていた乗じょう客きゃくが一いっ斉せいに乗のり込こんだ。

The moment the train arrived at the station, the waiting passengers all boarded at once.

Check yourself

1How is 否 read in か否か?

Choose an answer to see why.

2You are talking to a friend. Which sounds natural?

Choose an answer to see why.

More detail

否いな is also in 否いなめない, "cannot be denied", and, read いや, in 否いや応おうなく, "whether you like it or not". In words like 合ごう否ひ, pass or fail, and 可か否ひ, allowed or not, it is read ひ and still says "or not".

More sentences

その行こう為いが違い法ほうであるか否いなかを慎しん重ちょうに検けん討とうする必ひつ要ようがある。

Whether the act is unlawful needs to be examined carefully.

結けっ果かが統とう計けい的てきに有ゆう意いであるか否いなかによって、結けつ論ろんは大おおきく異ことなる。

The conclusion differs greatly depending on whether the result is statistically significant.

提てい出しゅつ者しゃが会かい員いんか否いなかを受うけ付つけで確かく認にんする。

Reception checks whether the person handing in the document is a member.

Straight after a noun.

制せい度どの見み直なおしが必ひつ要ようであるか否いなかは、今こん後ごの利り用よう状じょう況きょうを踏ふまえて判はん断だんする。

Whether the system needs to be reviewed will be decided in the light of how it is used from now on.