It’s 20 to 7 (Official clock system).

06:40

It’s 20 to 7.

Correct answer

07:20

It’s 20 past 7.

Error: mirror minute hand about the vertical axis

06:52

It’s 8 to 7.

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

08:30

It’s half past 8.

Error: confuse hour and minute hands