There are ways to ask favors - " can you please do this for me? " is probably the most easiest way to ask. The possible response to this question or favor can be an YES or a NO.. or sometimes lets see or maybe. I remember reading a book on good salesmanship few years ago and the author says that a salesman must never ask a question such us "Will you buy this product?" for the answer in most cases will be a NO. The salesman hence is advised to rephrase the question thus "wouldnt you surely buy this product?" or something like that. According to the author such questions on most occasions will get a positive response.
Language sure is quite an interesting tool. Recently I found myself chatting with my friend, my intention was to get a lift for a party. I told myself I will have to create a situation for her to ask me rather than me asking her. The reason is obvious, I really did not know her that well and really did not want a no for the answer. And so I started this chat conversation with her about the party and actually got her to ask me if she can give me a lift. Interesting. Later on as I was talking to her, she had a similar intention all along and was finding it a bit odd to ask me.
How complex can we get? But thats exactly what makes a conversation interesting. We had a great laugh over it.