15 минут девятого - It's a quarter past eight

пять часов - It's five o'clock sharp

без 15 четыре - It's a quarter to four

половина седьмого - It's half past six

без 15 десять - It's a quarter to ten

без 27 минут восьмого - It's twenty seven to eight

15 минут второго - It's a quarter past one