Alternatively, in the languages I speak:

Welche Sprachen sprechen Sie? (Deutsch/German)

¿Qué idiomas habla usted? (Español/Spanish)

Quelle langue parlez-vous? (Français/French)

EDIT: These sentences are now up to date.

  • @Droggelbecher
    link
    330 days ago

    It is indeed normal to use ‘du’ pretty much everywhere on the internet. Even in French i never see ‘vous’ (which to me feels more common than Sie in German usually).