Children, could you all pay attention please.

[Winwin2011]

I read the following sentences from Cambridge Grammar of English-R. Carter & M. McCarthy.

1. Children, could you all pay attention please.
2. Everybody, could you all hand in your evaluation as you leave, please.
3. Excuse me, waiter, sorry, could we have some more water, please?

At the end of sentences 1 and 2, they use a full stop. However, at the end of sentence 3, they use a question mark? Why are they different? Could anybody explain it to me, please?

Thanks.

[Rover_KE]

1 and 2 are polite ways in which a teacher gives instructions, instead of:

'Pay attention!'

'Hand in your evaluation as you leave.'

3 is a polite request from a diner to a server. You would not say to your waiter 'Bring us more water!' (I hope.)



Rover