I have noticed there are two main ways people order food. I often hear people asking if they can have such and such, like, “Can I have a cheeseburger and fries?” as if they may not get what they want unless they ask nice enough.
That’s not the way to do it. Just politely order the damn food. “I will have a cheeseburger and fries”. Period.
I typically say, I’d like a cheeseburger & fries please.
There’s always a small chance they’ve run out of something. I’ve had it happen at IHop several times. I order the Smokehouse Combo and sometimes they’re out of the sausages. I guess it’s a popular option.
I just tell them to give me ham when they’re out of the sausage.
Why? It’s a normal and common turn of phrase, and it makes the exchange flow better if they are out of something.
“I will have a cheeseburger and fries.” on the other represents an overconfidence in the immutability of menus and supplies. The future is fluid, man. It’s fluid!
I ‘ask’. It probably doesn’t really matter one way or the other This is the first time I’ve ever given it any thought but if I had to argue that side of the debate, I’d say that I ask for the food because I’m asking them to bring me my order, not demanding that they do it. And, really and truly, that’s what it is, you’re asking them to do something for you. They could decline your request. And, I think it sounds more polite.
I also, to some degree, thing the grammar sounds better to say “Can I get a burger and fries” vs “I will have a burger and burger and fries”. They may very well both be correct, but the latter sounds like an incomplete sentence.
In the end, I’d assume most people just order the way they hear others do it. maybe it’s even a regional thing. It also wouldn’t surprise me to find that the “I’ll have”/“I’ll take” group averages higher on the self confidence scale than the “Can I get…” people.