Asking for things in bars\shops etc - Imperative or Indicative Mood
I was under the impression that when asking for things, in places like shops or bars, you should use the imperative mood. However, I have increasingly seen examples where just the normal indicative mood is used. For example:
Me da una bolsa.
Me pone una cerveza.
I have seen\heard these used, but to me they mean:
You are giving me a bag.
You are giving (placing) me a beer.
This, to my non Spanish ear, sounds odd when asking for things. I would expect to hear:
Da \ Déme una bolsa (por favor)
Ponga \ Ponme una cerveza (por favor)
Give me a bag please.
Give (place) me a beer please.
The imperative sounds much more natural to me but, as I said earlier, I am increasingly hearing the indicative used for this type of request.
Are these moods simply interchangeable with this sort of request? Are there any subtle differences in meaning in these situations? What is commonly used in the Spanish speaking countries where you live?
As always, thank you so much for your help - I will crack this one day I promise 
1 Answer
I have seen\heard these used, but to me they mean:
You are giving me a bag.
Not really. They are in fact questions, and they are intonated as such:
¿Me da [usted] una bolsa?
English does not use questions like this without using modal verbs, but in Spanish this is normal for politeness:
¿Me ayudas? (literally: Do you help me? Correct translation: Can you help me?)
This, to my non Spanish ear, sounds odd when asking for things. I would expect to hear:
Da \ Déme una bolsa (por favor)
That is a command (it should be "dame", by the way), but I would only use "dame" with younger people, and always with a nice intonation, so it doesn't sound bossy.
