Quick answer
Здра́вствуйте · Приве́т
zdrávstvuyte / privét — polite and informal — the choice matters
The options
Здра́вствуйте.Hello. — polite, anyone, any time
Приве́т!Hi! — friends, family, people your age
До́брое у́тро.Good morning. — until about 11
До́брый день.Good afternoon. — the safe daytime greeting
До́брый ве́чер.Good evening.
Здра́вствуй.Hello — polite in form, but to one person you know
The word that scares beginners
Здра́вствуйте has four consonants in a row and nobody pronounces them all. In practice it sounds like “zdrás-tvuy-tye”, and in fast speech almost “drás-tye”. Say it that way and you will sound more native, not less.
What you hear back
Здра́вствуйте!Hello! — mirror what you were given
Приве́т! Как дела́?Hi! How are you?
О́чень прия́тно.Nice to meet you. — after an introduction
Typical mistakes
Приве́т to an official or an older stranger
Здра́вствуйте
приве́т is for people you would call ты.
До́брой но́чи as a greeting
До́брый ве́чер
Споко́йной но́чи is what you say when leaving, not arriving.
Check yourself
You greet your friend’s grandmother. What do you say?
Anyone older than you gets здра́вствуйте.