1 Tom plays football on Saturday. Tom doesn't play football on Saturday. Does Tom play football on Saturday?
2 I'm wearing a suit now. We don't wear suits every day. Are you wearing a suit now?
3 They do their homework in the afternoon. Do they do their homework in the afternoon? Ну и наверное вы имели в виду, что нужно отрицание поставить. Если да, то оно будет выглядеть так: They don't do their homework in the afternoon.