It’s 9 to 8 (Alternative clock system).

19:51

It’s 9 to 8.

Correct answer

19:50

It’s 10 to 8.

Error: 1 minute earlier

18:49

It’s 11 to 7.

Error: read minutes starting from hour markings and adding minutes

22:35

It’s 25 to 11.

Error: confuse hour and minute hands