Another user provided an example and I have added others:

Key to exercise
Key for exercise

Answer to a problem
Answer for a problem

Bullet to a gun
Bullet for a gun

She bought a taser to self-defense.
She bought a taser for self-defense.

We give alms to the poor.
We give alms for the poor.

She gave the order to the cook.
He put in the order for dinner.

Some of these seem pretty clear to me. I would select {to, to, for, for} for the first four, but the last two made me wonder if there is some rule at work, or if I'm basing it off what sounds better from repeated hearing. For instance, I might give "alms to the poor," but if I were poor then I'd bother passerby with "Alms for the poor?"

Is there some "pairing" going on (i.e. an answer is always to a question/problem/etc.)? Perhaps by plugging words into "this goes to that" or "this is for that", one could determine the proper usage. I'm looking for an explicit description or "rule" of what feels like an innate quality of the words. I believe Spanish has a similar dichotomy with para and por, but I'm not sure whether this translates (no pun intended) to English.

  • Please note that the last two examples (alms/order) weren't necessarily meant for direct comparison, but to show there's some nuances there that sometimes seem to involve the verb employed, perhaps some kind of possession or action, while other times it's a mystery to me (i.e. the trick for these formulae is always carry the one vs the trick to these formulae is always carry the one).
    – Zairja
    Aug 10, 2012 at 16:10

3 Answers 3


Here's part of an explanation found here:

TO ... is used in cases where a "transfer" happens. E.g.

  • I will give this book to you. (from me to you)
  • I will go to work. (from home to work)
  • I will talk to her. (information goes from me to her)

FOR is used in the following situations:

for the benefit of

e.g. I will do that for you.


e.g. This brush is for painting.

Not exactly a rule, but in general to applies if the word coming afterwards is specific. For is used if the situation is more abstract.

For this reason, both of your examples for alms make sense depending on the context.

We give alms to the poor.  (Which poor? The beggars downtown. We give alms to those beggars.)  
We give alms for the poor. (Which poor? I'm not sure. Our charity determines who receives the alms.)
  • But this cream is for putting on your spots can just as easily be this cream is to put on your spots. Certainly in the case of this medicine is for helping you sleep, I would prefer this medicine is to help you sleep. Any "rule" is sporadically applied - idiomatic usage is everything. Aug 10, 2012 at 16:35
  • @FumbleFingers It seems you're right about idiomatic usage. I tried to think of the most ambiguous statement I could. The closest ones I came up with were "he wrote a letter for/to her", which could be interpreted as writing a letter on someone's behalf rather than addressed to them, and "she left a key to/for the housekeeper", which might sound like a transfer of key ownership rather than to lend a key to use. I'm comfortable with my use of to/for, but teasing out how/why I use one or the other seems to depend on the factors in the answers, as well as usage. +1 to all, thanks
    – Zairja
    Aug 10, 2012 at 17:20
  • 1
    @Zairja: I think you over-analysing the "meaning" of these different prepositions. As Daniel says here, even when you can identify a tendency to use certain words in certain constructions, what you've got is "not exactly a rule". If you're a native speaker, you're already familiar with which prepositions are used in which constructions - but sometimes even that differs across regions, educational or other social divisions, etc. If you're not a native speaker, mostly you just have to learn them one by one. Aug 10, 2012 at 21:02

"To" specifies a direction, an intention, it implies some action, while "for" is more associated with someone/something who is intended to own or use the noun preceding "for".

key to exercise - I cannot find a key to this exercise. key for exercise - The keys for the exercises are on the last page.

bullet to a gun - The police could not find any bullet to the gun in the street. bullet for a gun - We took a lot of bullets for a gun when hunting.

  • I think you'd almost never come across bullet to the gun - for the sense intended, it would be bullet matching the gun or something similar. Aug 10, 2012 at 16:39
  • You are right, I could not find any better example for that expression.
    – Arsen Y.M.
    Aug 10, 2012 at 16:42
  • @FumbleFingers You can link a bullet to a gun. #csi Aug 10, 2012 at 17:34
  • ammunition for my gun.
    – Charles
    Aug 10, 2012 at 18:42
  • 1
    @coleopterist: Obviously you can "link a bullet to a gun", and vice-versa. I'm just saying that in practice native speakers wouldn't normally say anything like "The police found the bullet to the gun". Aug 10, 2012 at 20:56

I do not have a clear answer, but the question poses some ambiguity issues.

Part of the problem is the characterization that the prepositions are used between two nouns. In the cases listed, that is physically true. This seems to imply the prepositions define the grammatical relationship between those nouns. That is not necessarily the case.

In the example

She gave the order to the cook.

the phrase to the cook is not a modifier of order, it is the indirect object of the verb gave.

However, in the example

He put in the order for dinner.

the prepositional phrase for dinner is a modifier of the noun order.

Similarly, in

We give alms to the poor.

the phrase to the poor is the indirect object of give.

I believe (but am not certain) that indirect objects are often introduced by to but not usually by for

If that is so, in

We give alms for the poor

the phrase for the poor should be interpreted to be a modifier of alms.

By no means am I suggesting that to cannot introduce a noun modifier, but in some of these cases, it does not.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.