AかBか

Whether a or B

Level 2Sounds Like ka ka

The pattern AかBか (A or B) is used to list two possibilities. It can be a direct question asking for a choice, or an 'embedded question' (e.g., 'I don't know whether A or B') within a sentence.

How It Works

The AかBか pattern is highly versatile and appears in both casual and formal Japanese.

1. Formation Rules:

  • Verbs: Use the plain form (including past tense). Example: 買ったか買わなかったか (Whether I bought it or not).
  • I-Adjectives: Use the plain form. Example: 高い（たかい）か安い（やすい）か (Whether it is expensive or cheap).
  • Nouns: Attach directly without the copula だ. Example: 肉（にく）か魚（さかな）か (Meat or fish).
  • Na-Adjectives: Attach directly without だ or な. Example: 好き（すき）か嫌い（きらい）か (Whether you like or hate it).

2. Usage Scenarios:

  • Direct Questions: When asking someone to choose. In polite speech, this often becomes Aですか、Bですか.
  • Embedded Questions: When the choice is the object of another verb like 'to know' (知る（しる）), 'to decide' (決める（きめる）), or 'to understand' (わかる).

3. Grammatical Function:
The entire AかBか block acts as a noun clause. This means it can be followed by particles like を or が. For example: 「行くか行かないかを決めてください」 (Please decide whether you will go or not).

4. Nuance:
Using AかBか instead of just AかB makes the options feel more distinct and balanced, especially when the options are full actions (verbs) rather than just simple nouns.

Examples (4)

  1. 行くか行かないか、早く決めてください。

    Please decide quickly whether you are going or not.

    Word by Word: Go or not go, quickly decide please.

    This uses the verb in its positive and negative plain forms to create a 'whether or not' choice.

  2. それが本当か嘘か、私にはわかりません。

    I don't know whether that is the truth or a lie.

    Word by Word: That (subject) truth or lie, to me is not known.

    Here, two nouns (本当 and 嘘) are used. Notice that the copula だ is omitted before か.

  3. 肉か魚か、どちらがいいですか。

    Meat or fish, which would you prefer?

    Word by Word: Meat or fish, which is good?

    This is a direct question presenting two noun options using the question word どちら (which).

  4. 新しいパソコンを買うか買わないか迷っています。

    I am hesitating over whether to buy a new computer or not.

    Word by Word: New computer (object) buy or not buy, am hesitating.

    The choice 'to buy or not' is embedded as the reason for the hesitation.

Common Mistakes

  • Including the copula 'da' with nouns or na-adjectives.

    好きだか嫌いだかわかりません。
    好きか嫌いかわかりません。

    When using か with nouns or na-adjectives in an embedded question, you must drop the casual copula だ.

  • Using 'to' (and) instead of 'ka' (or) when presenting choices.

    コーヒーと紅茶、どちらがいいですか。
    コーヒーか紅茶、どちらがいいですか。

    While 'A to B' means 'A and B', 'A ka B' is required when you are asking for a choice between the two.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

AかBかLevel 2Whether a or B

Learn This First

To understand 'AかBか', you first need to be comfortable with the question particle 'か' and how it marks uncertainty. Since this pattern often acts as a clause within a larger sentence, familiarity with basic sentence structure and how questions can be embedded into other phrases is essential.

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