one hour and fifteen minutes

This is a formal way to tell the time. When you tell the time formally, you do the following:

say the precise time instead of rounding it up or down

use "one hour" instead of "an hour"

say the number of minutes instead of using "and a half"

Here's a casual way to specify the time:

an hour and a half

Here's how you talk about the time formally:

one hour and thirty-three minutes

This phrase appears in these lessons: