Here are some of the ways of saying what time it is.

For the time 4:00:

Four

Four o'clock

For the time 4:15:

Four fifteeen

A quarter after four

A quarter past four

For the time 4:30:

Four thirty

For the time 4:45:

Four forty-five

A quarter to five

For the time 4:05:

Four oh five

Five after four