A grammar question

Here is some choices, which one is correct?
a. All you had to do was buy a card.
b. All you had to do was to buy a card.
c. All you had to do was buying a card.

It’s from the sitcom Friends (7*14).

A and B are acceptable. B is more emphatic.

thanks for your answer.
But I think the correct choice should be C, because -ing is like a noun and here, we need an object (buy a card) as in the sentence(All … was).
I don’t understand why A and B are both correct but C is not.
BTW, A is used in the show, which confused me.

C is definitely wrong because after was you need the infinitive. As I say,A and B are acceptable. The only difference is that B is more emphatic/precise.

Look at this sentence: All you have to do is (to) answer the question. In that sentence and in your example all is the object of the verb do. If we open the sentence up, we get: You have to do all and that is (to) answer the question

Thank you very much Alan!

Your answer is very clear and helpful.

So, I made some sentences, are they all correct?

  1. One of my hobby is play tennis.
  2. The reason I love this forum is know a lot of knowledge about English.
  3. One of my dream is speak perfect English and understand what English speakers take about.

So, I HAVE made some sentences, are they all correct?

  1. One of my HOBBIES is [color=red]PLAYING tennis.
  2. The reason I love this forum is BECAUSE I [color=cyan]GET TO KNOW a lot about English.
  3. One of my dreamS is [color=cyan]TO SPEAK perfect English and understand what English speakers TALK about.

The main difference between the [color=red]gerund (ING form) and the [color=cyan]infinitive is that the [color=cyan]infinitive is more specific than the [color=red]gerund

Confused again:
You said “C is [color=red]definitely wrong, because after ‘was’ you need the infinitive”. But why you chose gerund in
“One of my HOBBIES is PLAYING tennis.”? Only because “play tennis” is not specific? If so, technically, C (“buying a card” from the first question) could be correct by grammar if I think “buy a card” is not very specific.

The sentence you are asking about (“All you had to do was to buy a card.”) is not just a simple sentence like “My hobby is playing tennis”. It is a special emphasizing structure which you use if you want to focus on an action performed by someone. It consists of “what” followed by the subject, the verb “do”, the verb “be”, and the infinitive clause with or without “to”.
You use “all” instead of “what” if you want to emphasize that just one thing is done and nothing else.

I have to take issue with you about your comment that the second sentence (All you had to do was buy …) is grammatically incorrect. Whose grammar is this? The missing to in the second half is understood/implied. I can’t accept that grammar is all right for the written word and not for the spoken word - a case in point because here I could leave out word. There is the spoken language and the written language but don’t start dragging in grammar as both have their own idiom. The sentence quoted is a sort of condensed one because if you opened it up you would write: All you had to do was you had to buy. You shorten this to either: All you had to do was to buy or All you had to do was buy. And quite frankly that is all I have to say or write on the matter. Alternatively that is all I have to say on the matter and all I have to write on the matter.

Thank you all guys!
I prefer the answer of Ella’s that “It is a special emphasizing structure”.
Anyway, it’s a really confusing grammar point, isn’t it?

I am glad you like it.

All you had to do was buy a card
All you had to do was to buy a card.
*All you had to do was buying a card.
In the sentences an action was expected to follow as complement. So both buy and to buy are acceptable. (Personally, I feel ‘buy’ better, than ‘to buy’.)

If you want any help, you have to ask.
From this we can see that ‘had to do’ can be replaced by ‘had to buy’.
You had to buy a card.
Therefore, ‘buy’ is enough. The repetition of ‘to’ is not necessary, as all the needed elements are present in ‘had to do’.

Look at these:
*He found buy a card difficult.
He found to buy a card difficult.
He found buying a card difficult.
In this set I have written, a noun is needed to complete. Therefore, we use the gerund.
He found ‘what?’ difficult.
#The sentences with the ‘
’ mark are incorrect.

Notice that the ‘had to do’ was not adding emphasis, but a sort of analysis andor finding fault with someone who did not do something required for the successful completion of a job.

hi, Narayanan Krishnaswamy:

What confused me is the verb after “Be”. Like my example:

a. All you had to do was buy a card. [correct]
b. All you had to do was to buy a card. [correct]
c. All you had to do was buying a card. [Wrong]

But:
a. One of my hobby is play tennis. [Wrong]
b. One of my hobby is to play tennis. [Wrong]
c. One of my hobby is playing tennis. [Correct]

In my oppion, There is not big difference between “buy a card” and “play tennis”. But the answer to the above two questions are totally opposite.

Anyway, I perfer Ella’s reply that the first one is “a special emphasizing structure”. That’s the reason why it use infinitive. Do you agree?

BTW, since you are from India, are you an English speaker?
Cause your English is pretty good.

It seems some more explanations may go well.
All you had to do was( to do what?) buy to buy a card.
He found( what?) buying a card difficult.
One of my hobbies is (what?) playing tennis. (Just tennis may also be enough or watching tennis.)
The first sentence requires an action as completion, whereas the next two require nouns.
I have to go.( It is already late so I must leave)
I had to buy.( There was a compulsion to buy, so I bought.)
All he had to do was to buy a card.
( Means, he did not buy the card. He should have done so. That would have turned the cards in his favor. Though there is no negative word in the sentence to indicate that he did not buy, the past perfect combined with ‘all’ gives the meaning. The ‘all’ has a special meaning – the only thing.) The sentence means—the only thing he had to do was buy a card, which he did not do.
Next you have written “one of my hobby …”
‘One of the’ is always followed by a plural—hobbies.
I am an Indian, a Professor of English, serving a college in South India. I am a non-native English teacher.

Thanks for noticing me agin. Alan correct me last time, but I did it again. :stuck_out_tongue:

Well, that explains why you get good English!

Something still confuses me: why can’t I look it in this way:
All you had to do was (what?)
So, I can put “buying a card” there.

Sorry that your method didn’t ring any bells to me. :frowning:

I was writing on intuition and in a casual manner, with what I have learnt and referred to long back.
Saying that ‘my method did not ring any bells’, made me refer to books.
Prof. N. Krishnaswamy, former Head of the Deapartment of English, Central Institute of English and Foreign Languages, Hyderabad has written a grammar book , ‘ Modern English.’ He is the present day authority on usage .The book was published by Macmillan India.
In page 245, in a chapter dealing with infinitives, he gives an example:
All you have to do is to sit down and faithfully copy it.
This is the very near sample, I could get, to that of our discussion.
Next
A Handbook of English Grammar by R.W. Zandvoort and Van Ek gives the example:
I had hoped to catch the 8.30, but found it was gone.
She had intended to call but was prevented by a headache.
Here the actions did not materialize. Even like that—All he had to do was to buy a card, which he did not do.