It’s 21 past 12 (Official clock system).

00:21

It’s 21 past 12.

Correct answer

00:22

It’s 22 past 12.

Error: 1 minute later

00:05

It’s 5 past 12.

Error: read minutes starting from hour markings and adding minutes

04:00

It’s 4 o’clock.

Error: confuse hour and minute hands