Questions & Answers about Пожалуйста, не звони поздно ночью.
What verb form is звони, and what does it tell me about how I’m addressing someone?
Звони is the 2nd-person singular imperative of the imperfective verb звонить. It addresses one person informally (the ты form). So the sentence is a polite request to someone you talk to as ты.
How do I say it to more than one person or politely?
Use the вы-form of the imperative: Пожалуйста, не звоните поздно ночью. That can address multiple people or one person formally.
Why is it звони (imperfective) and not позвони (perfective) after не?
In negative imperatives, Russian usually uses the imperfective: Не звони = “Don’t (ever/in general) call.” The perfective negative imperative (Не позвони) is rare and sounds unnatural or very marked here. There are exceptions with certain verbs (e.g., Не забудь “Don’t forget”).
If I want to be explicit that they shouldn’t call me, where do I put мне?
Say: Пожалуйста, не звони мне поздно ночью. The verb звонить governs the dative case: звонить кому? — мне, маме, врачу. With institutions, you’ll often hear звонить в банк/в полицию as well.