English, as many languages, does not have a brief way of distinguishing a mechanistic 'why'; from a teleological 'why'.
Q: Why does the hammer on a piano strike the string then retract to its resting position?
Mechanistic answer: since it is unsupported, gravity pulls it back down.
Teleological answer: well, if it didn't retract, then it would dampen the sound, which is not what the piano designer intended.
Q: Why is the sky blue?
Mechanistic answer: higher frequencies of light scatter off of the small molecules in air more easily than the lower frequencies of light.
Teleological answer: er... god, umm.. well, that's the way it should be.
Q: Why do we pay taxes?
Mechanistic answer: er... it's sort of complicated. I dunno.
Teleological answer: if we didn't pay taxes, the IRS would have us arrested. Anyway, the money we provide to the government allows it to provide us with vital services like education, roads and other infrastructure, police to keep people from violating us or the commons, an army to keep us safe from invaders, and a Federal Government to laugh at hysterically.
As you can see from the later two examples, many questions are unambiguous since there is only one reasonable way to answer the question. However, some questions, especially concerning design, need to be specially disambiguated.
English also lacks a form of 'to be' which implies that the predicate is 'definitional' or always so.
"My grapes are delicious."
Do I mean that all grapes I ever have are delicious? Such a statement makes sense if I grow grapes. Or do I mean that the grapes I have at the moment are delicious?
Of course, this lack may actually be an advantage, since such strong statements tend to be dangerous.
'You' does not indicate number
When you said "You", did you mean "me" or "him and me"?
We used to have this - thou was reserved for singular familiar, in an arrangement similar to other western languages. Gradually, the restrictions on who was familiar enough you could use this became tighter and tighter; now, it only applies to God. With whom no one is even on speaking terms. Go figure.
'We' can include the addressee, or not.
When you said "We", did you mean "you and me", or "you and him"?
vuo says: the Sámi language and proto-Fennic in general has two "we's", "we two here" and "we" in any other sense
So it's official, that is not an entirely unreasonable thing to expect from a language!
To answer the limitation raised in the first writeup (of desire straight-up vs. desire tempered by reality), I often introduce the dichotomy of "wish" and "want". "Wish", I reserve for the situations in which judgement overrides the desire (including cases where I have not yet made up my mind). "Want", I reserve to mean what my judgement tells me to do.
Since this distinction is not explicit in the language, I make sure I have mentioned this to someone before I rely on the distinction. Still, it's intuitive enough that I guess I could.
"I wish to have some ice cream." (but I'm on a diet, so I won't)
"I want to have some ice cream." (screw the diet)
"Do you wish to pull his liver out with your bare teeth?" (answer could be 'yes')
"Do you want to pull his liver out with your bare teeth?" (answer is almost certainly 'no')
"I do not wish to put my dog to sleep." (who would wish to?)
"I want to put my dog to sleep" (because she has an excruciatingly painful stomach cancer which would kill her slowly over the next week)