half (an) hour

[nyota]

A: How long do you think it'll take you?
B: Oh, I'm not sure, half an hour/ half hour?

Are both half an hour and half hour correct?

[Mannysteps]

NOT A TEACHER

The usual in the context is "half an hour". There is "half-hour" used for a period of 30 minutesand the middle point of an hour.

M.

[emsr2d2]

A: How long do you think it'll take you?
B: Oh, I'm not sure, half an hour/ half hour?

Are both half an hour and half hour correct?

In this example, I believe we have another BrE vs AmE split.

BrE: It'll take half an hour.
AmE: It'll take a half hour.

As Mannysteps said, "half hour" is used to describe the point halfway between two exact hours.

The church bell strikes once on the half hour, all day and all night!

(Note: it probably chimes on the hour as well, but the sentence above only means that it strikes at 30 minutes past every hour.)