At 4 pm we usually sleep (спим)

Аt 6.15 pm we usually read newspapers (читаем газеты)

Аt 12.40 аm we usually sleep (спим)

Аt 10.30 pm we usually go to bed (собираемся ко сну)

Аt 12.50 pm we usually sleep (спим)

Аt 9.40 pm we usually talk about news (рассказываем о новостях)

At 4 pm my parents and I usually go for a work. - 16.00 

At 6.15 pm my family and I usually have supper. - 18.15

At 12.40 am we usually play chess or read books. - очевидно, вы ошиблись, здесь 12.40 am (иначе все теряет смысл) - 12.40 (дня)

At 10.30 pm my family and I usually go to bed. - 22.30

At 12.50 pm my parents and I usually sleep. - 0.50 (глубокая ночь)

At 9.40 pm we usually watch TV. - 21.40