What does “вы не подскажете” mean in Russian?

The politest way to stop a stranger in Russian is вы не подскажете...?, “could you tell me...?” It is a negative question, “won’t you tell me?”, and the не makes it softer, not ruder. Подсказать means “to prompt” or “to give a hint,” so you’re asking for a small piece of help: вы не подскажете, как пройти к метро?

The same softening не works elsewhere: вы не знаете...? (“do you happen to know...?”), у вас не будет ручки? (“would you have a pen?”). Подсказка is a hint, also the “prompt” in a quiz. In the clip a tourist asks вы не подскажете, как мне попасть вот на эту улицу? and gets прямо и налево.