It’s 21 past 6 (Official clock system).

18:21

It’s 21 past 6.

Correct answer

18:22

It’s 22 past 6.

Error: 1 minute later

18:05

It’s 5 past 6.

Error: read minutes starting from hour markings and adding minutes

16:30

It’s half past 4.

Error: confuse hour and minute hands