It’s 20 to 10 (Official clock system).

09:40

It’s 20 to 10.

Correct answer

10:20

It’s 20 past 10.

Error: mirror minute hand about the vertical axis

09:52

It’s 8 to 10.

Error: read minutes as hours with ‘past’ or ‘to’

08:45

It’s a quarter to 9.

Error: confuse hour and minute hands