誰か・どこか・誰も・どこも

This group of words is used to refer to people or places in a non-specific way. 誰か and どこか point to a positive, non-specified person or location (Someone, Somewhere). When you want to say that no one or nowhere, you use 誰も and どこも, typically with a negative verb form. The nuance is about the speaker not naming the person or place, either asserting a positive existence (誰か/どこか) or denying it (誰も/どこも). Typical contexts include conversations about unknown parties, general possibilities, or negative statements about existence. Examples: - 誰かが来た。 Someone came. - どこかで雨が降っている。 It is raining somewhere. - 誰も来なかった。 Nobody came. - どこにも行けない。 I can’t go anywhere. - 誰かが助けを求めている。 Someone is asking for help. - どこかでその話を聞いた。 I heard about it somewhere.