His reason ________ was _______ fish.
for going for buying
to go to buy

Can someone please explain which of the alternatives is correct, please.
Explanations as to why would also be greatly appreciated.


Can someone please explain which of the alternatives is correct, please.
Explanations as to why would also be greatly appreciated.

His reason _for going was to buy fish. I think this sentence is lacking in context. Nonethelss, when we look for an explain or a reason in this structure, the verb followed is almost always gerund but the action to be performed is alway infinitive. i.e. Her reason for calling in sick yesterday was to go to the dentist

But her boss told her that's was not reason enough to call sick.

The landlord didn't have enough reason to evict the tenant.

The landlord's reason for evicting the tenant was their failures to pay rent according to the rental agreement.

So you see, when the context changes, the rules may change as well.
The explanation is long and complex - below is a quick , simple and not very well laid out explanation

The problem here arises because the infinitive is said (by those who studied Latin at school and those who believe their teachers who were told by those who studied Latin at school) to be "to go", "to do" etcetera. This is just wrong, as study of Anglo-saxon and even modern German shows. The word "to" in front of a verb usually denotes purpose (present or future purpose relative to the tense of the principal verb).

In the example, the 'purchase of fish' was the purpose and can be denoted by "to buy", whereas the going is not a purpose, rather it is a means to an end. However "his reason to go" is frequently used colloquially but it is better to use "for going" in this context (standard idiom in England).

Now we can say "His frequent visits to London were for fun". Note, here, the use of a noun "fun". Where a noun can be used it is usually possible to use "for " and the "gerund" (e.g. for having fun). But note, here the emphasis of the sentence is less on the purpose more on the frequency and the location. "His frequent visits to London were to have fun" emphasises the purpose.


  1. "to" + infinitive denotes purpose
  2. where a noun would be natural, "for" plus the gerund is acceptable though in ordinary speech, it might be considered rather an elevated style.
  3. use "to" + infinitive to emphasise purpose

  4. The questions you should ask yourself are, as follows:

    Is it a purpose? If yes, can a noun be used? If yes, do I wish to emphasise purpose or use an elevated style of speech?

    Sorry for the long-winded explanation
Teachers: We supply a list of EFL job vacancies
His reason for going was to buy fish. (correct)

Well, it's hard to explain why. I am really sorry. I am not a native English speaker, but I just know by experience and by instinct which to use, depending on the context.

My advice is to find a lot of examples and read them over and over again. Then, spot the difference in context and get the "feel" of it. I'll leave you with some examples.

REASON FOR DOING SOMETHING - a fact, situation, or intention that explains why something happened, why someone did something, or why something is true.

1. Don't ever leave me, or I'd die! You are my reason for living.
2. Could you explain your reasons for choosing this particular course?
3. His reasons for ending his own dear life were kept a secret.
4. Your reason for being jealous a while ago was totally invalid and unacceptable. We were just talking! We were not kissing or hugging or holding hands or anything like that! Why can't you trust me! I'm sick of your jealousy!
5. A: Why did you have to come to my party like that?
B: My reason for coming to your party and for behaving that way was not only to annoy you, but to embarrass you like you did to me! It was quite satisfying to do that.

REASON TO DO SOMETHING - a good or clear cause for doing something or thinking something.

I can't find any reason to celebrate.
3. I have every reason to hate you! You ruined my life!
4. She has no reason to shout at you.
5. Is there still any reason for me to hold onto you?

to go / going