Question about the particular use of 'か'


  1. 今日 **か** あした来てください。 (Please, come today or tomorrow)
  2. 行く **か** 行かない **か** 、わかりません。(Go or not, I don't know)

I guess in these two cases 'か' means 'or', but why is there no 'か' after
'あした'. In example 2 there is a 'か' after '行かない'. It is because you are
'counting' the possibilities? Need someone to clear that up for me. Thanks a
lot!




Grammatically speaking, か in Sentence 1 and か in Sentence 2 are a bit
different.

In Sentence 1, か is simply like "or". In this case, the second か is optional,
but is _usually omitted_ in modern Japanese.

>   * リンゴかバナナ(か)を買う。
>   * 私か佐藤さん(か)が行きます。
>

In Sentence 2, the two か's are forming two [embedded
questions](https://japanese.stackexchange.com/a/13038/5010) placed in
parallel. In this case, か cannot be omitted (but the particle _after_ the か is
usually omitted, as described in the link).

>   * 京都に行くか東京に行くか(を)決めましょう。
>   * 生きるべきか死ぬべきか、それが問題だ。  
>  To be or not to be, that is the question.
>




Grammatically speaking, か in Sentence 1 and か in Sentence 2 are a bit
different.

In Sentence 1, か is simply like "or". In this case, the second か is optional,
but is _usually omitted_ in modern Japanese.

>   * リンゴかバナナ(か)を買う。
>   * 私か佐藤さん(か)が行きます。
>

In Sentence 2, the two か's are forming two [embedded
questions](https://japanese.stackexchange.com/a/13038/5010) placed in
parallel. In this case, か cannot be omitted (but the particle _after_ the か is
usually omitted, as described in the link).

>   * 京都に行くか東京に行くか(を)決めましょう。
>   * 生きるべきか死ぬべきか、それが問題だ。  
>  To be or not to be, that is the question.
>

