It’s 20 to 4 (Official clock system).

03:40

It’s 20 to 4.

Correct answer

04:20

It’s 20 past 4.

Error: mirror minute hand about the vertical axis

03:52

It’s 8 to 4.

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

08:15

It’s a quarter past 8.

Error: confuse hour and minute hands