difference
Currently i am reading a book called 'Lick' by Kylie Scott
I came across the above phrases on pg 89 – 90 where the lead character asks this question or uses expression in the following ways – that are
I was wondering what's the difference in those.
The only difference would be that some people insist that you should not end a sentence with a preposition. (This has been asked both at ELU and here on ELL.)
Those people would consider the sentence "What are you going to die for" wrong.
However, it is very common and widely accepted to end a sentence with a preposition, so both sentences are fine. Just be aware there will be people who consider the "for what" as "better".
Note that "What for?" is informal/conversational.
"What for" denotes a purposeful reason, while "Why?" can be used for causes, reasons, or explanations.
Why? OR What for? (Purpose): "To make money."
Statement 2: "Things fall."
What for (purpose only!): "Who knows? God? Quantum Multiverse? That may not be answerable."
Statement 3: "I exist."
Variations can be created by sentences like "What is $NounPhrase$ for?" For example, if one is in a new car with a salesman, one can ask "What is that button for?" In this case, the question is asking for the functional purpose of the button. Also, "What is math good for?" is asking for suitability for a purpose.
"What for" can lend itself to more emotion than a simple "Why", adding surprise, suspicion, or just more emphasis. In this case, "what for" can be asking for an explanation just like "why":
The emotion behind "What for?" can also be suspicion or interrogation. There can be a bit of eye squinting or head tilting:
"Can I ask you your name?"
"Ummm. What for?" (Suspicion)
"What for" can also be used to mean "For what?" in order to identify an ambiguous reference. The emphasis is on replacing the "what" with the named item rather than replacing the "for" with the named reason:
Here's another one:
Both "what for" questions could be asking for purposeful reason. For example, in the 2nd case, the reason could have been to clean the shelf. But the answer given in the 2nd case was an identification of the object desired.
Also, "What am I responsible for?" is asking for identification of responsibilities. It is like "For what am I responsible?", but the fronted what sounds more natural.
Best Answer
There is very little difference.
In the case of sing for, the singer may simply be singing aloud; the singing is not necessarily directed at the listener, it just fills the environment.
In the case of sing to, the singer is singing directly at the listener.