It’s 20 past 4 (Official clock system).

16:20

It’s 20 past 4.

Correct answer

15:40

It’s 20 to 4.

Error: mirror minute hand about the vertical axis

16:16

It’s 16 past 4.

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

16:00

It’s 4 o’clock.

Error: confuse hour and minute hands and read as full hour