If we try hard enough, we can win the game.

[MichaelLu2000]

1. If we try hard enough, we can win the game. (O)
2. If we try hard enough, we will be able to win the game. (O)

3. If I study hard, I can speak Chinese. (X)
4. If I study hard, I will be able to speak Chinese.(O)

Why do 1 and 2 both sound okay while in the second pair (3 & 4) only "will be able to" is acceptable?

 

[emsr2d2]

At the moment, they're all wrong because they don't have a closing full stop. What do "(O)" and "(X)" mean? Use "OK" or "okay" but not "ok".

 

[MichaelLu2000]

At the moment, they're all wrong because they don't have a closing full stop. What do "(O)" and "(X)" mean? Use "OK" or "okay" but not "ok".

O is okay and X is not okay. Anyway, I have edited it.

 

[MichaelLu2000]

One of the possible causes of the difference that I can think of is that using "can" implies the possibility of doing something while using "be able to" means the acquirement of the ability to do something, but I don't know if that's a logical explanation.

 

[Barque]

Chien Te Lu, I think that's a good explanation. It's one of those things that are hard to explain.

the acquirement

The noun form is "acquisition".

 

[emsr2d2]

One of the possible causes of the difference that I can think of is that using "can" implies the possibility of doing something while using "be able to" means the acquirement of the ability to do something, but I don't know if that's a logical explanation.

I don't agree with that difference.

Helen: Can you touch the tip of your nose with your tongue?
Sarah: Yes. (Demonstrates.)
Helen: Wow! How did you learn to do that?
Sarah: I didn't. I've always been able to do it.

When I was a kid, I was able to hold a handstand for thirty seconds. Now I can't even get into a handstand!

 

[jutfrank]

I'll guess that the reason you think sentence 3 is 'unacceptable' (it isn't), is that the words I can speak Chinese are supposed to be talking about a general ability rather than a specific ability for a specific time.

If I study hard, I can pass the test tomorrow.

That's fine, right? There's a specific ability for a specific future time. Just like in your 'We can win the game' example.

Now imagine the test tomorrow involves speaking Chinese, which is something that you can do only if you study hard. You believe that if you study hard, you'll have the ability to say some things in Chinese. It may be that after the test you forget everything you've learned, but still, you'll have the ability to speak Chinese for the specified duration of the test.

If I study hard, I can speak Chinese (tomorrow).

I hope that with the bracketed word 'tomorrow' in place it now makes sense. Yes, it's a silly example, but it makes sense as long as the meaning is clearly understood to be ability at a specific future time.

Now, if what you really want to say is something about a general ability to speak Chinese, then you're right that sentence 3 is wrong: you can't use can to talk about future general abilities—you have to use 'be able to'.

 

[MichaelLu2000]

I'll guess that the reason you think sentence 3 is 'unacceptable' (it isn't), is that the words I can speak Chinese are supposed to be talking about a general ability rather than a specific ability for a specific time.

If I study hard, I can pass the test tomorrow.

That's fine, right? There's a specific ability for a specific future time. Just like in your 'We can win the game' example.

Now imagine the test tomorrow involves speaking Chinese, which is something that you can do only if you study hard. You believe that if you study hard, you'll have the ability to say some things in Chinese. It may be that after the test you forget everything you've learned, but still, you'll have the ability to speak Chinese for the specified duration of the test.

If I study hard, I can speak Chinese (tomorrow).

I hope that with the bracketed word 'tomorrow' in place it now makes sense. Yes, it's a silly example, but it makes sense as long as the meaning is clearly understood to be ability at a specific future time.

Now, if what you really want to say is something about a general ability to speak Chinese, then you're right that sentence 3 is wrong: you can't use can to talk about future general abilities—you have to use 'be able to'.

Yes that’s what I want to say too!

If I study hard, I will be able to speak Chinese=I will gain the general ability to speak Chinese; when I use it is not the focus of the sentence.

If I study hard, I can speak Chinese in front of my father tomorrow=I will gain the specific ability and the actual speaking of Chinese will possibly take place tomorrow.

I think another way to interpret this is that “can” not only implies the specific ability but also the possibility of the actual happening.

Example: I can’t do anything right now, but if you give me more information, I can find the person you want=> I will gain the specific ability to find someone and thus the actual finding of someone becomes possible.

 

[jutfrank]

Yes, there is an obvious relation between ability and possibility. You can think of ability as just one kind of possibility, since if you are able to do something, then it is possible for you to do it, and conversely, if you don't have the ability to do something, it is not possible. In semantics, we would say that the sense of can to express an ability to speak Chinese has dynamic modality.

 

[MichaelLu2000]

Yes, there is an obvious relation between ability and possibility. You can think of ability as just one kind of possibility, since if you are able to do something, then it is possible for you to do it, and conversely, if you don't have the ability to do something, it is not possible. In semantics, we would say that the sense of can to express an ability to speak Chinese has dynamic modality.

Yes. But I think “If I study hard, I will be able to speak Chinese” doesn’t imply that possibility. It simply says I will gain the ability, but when and whether I am going to use that ability is not implied.

 

[jutfrank]

If you gain the ability, then you also gain the possibility. It doesn't matter whether or not you choose to use the ability—the possibility is still there.

 

[MichaelLu2000]

If you gain the ability, then you also gain the possibility. It doesn't matter whether or not you choose to use the ability—the possibility is still there.

Yes I know what you mean.

However,

“If I work hard, I will be able to speak Chinese”=> I will gain the ability to speak Chinese. The actual speaking of Chinese on an occasion will definitely become possible but this interpretation won’t be emphasized in this sentence.

“If I practice hard, I will be able to play the violin.”=>Again, I will gain the ability to play the violin. However, the possibility of the actual playing is not emphasized.

“If we work together, we can win this game”=> We will gain the ability and the actual winning will possibly take place after we work together.

I think it’s because “can” here implies the ability on a specific occasion along with the possibility of its actual achievement, while “will be able to” implies the general ability that you gain and keep for a long time; therefore, whether and when you are going to use that general ability is not the point.

A person who can ride a bike might never or seldom ride it in the future; by contrast, a man who say he can ride a bike to school tomorrow is implying he has the ability to ride it and the actual ridding “can” possibly take place tomorrow.

 

[jutfrank]

I see what you mean now. Yes, there is often a suggestion with can that if something can be done, it will be done.

I think one should be careful not to overgeneralise here, however, as it's not always the case. To get a firm sense of the modality of a particular word, you have to look at context of the utterance as a whole.

If we work together, we can win this game.

For this context, you're quite right that anyone would reasonably interpret the speaker here to be saying that there is an intention to win the game.

 

[MichaelLu2000]

I see what you mean now. Yes, there is often a suggestion with can that if something can be done, it will be done.

I think one should be careful not to overgeneralise here, however, as it's not always the case. To get a firm sense of the modality of a particular word, you have to look at context of the utterance as a whole.

If we work together, we can win this game.

For this context, you're quite right that anyone would reasonably interpret the speaker here to be saying that there is an intention to win the game.

I cannot agree with you more. Thank you very much.

I have just found a website that discusses the difference between future general and future specific abilities, as you mentioned in your earlier comments.

https://www.perfect-english-grammar.com/modal-verbs-of-ability.html

It confirms my opinion that "will be able to" emphasizes the acquisition of general abilities while "can" implies the possibility.

I will be able to make my own website at the end of this program.=>I don't have the ability right now (I don't have the knowledge and skills) but I will gain it at the end of this program.

I will come back to the office tomorrow; therefore, I can send the letter tomorrow=> Of course I already have the knowledge and skills to send a letter (write it, put it in an envelope, and then go to the post office to send it). What I want to emphasize is that this "can" be done tomorrow (sending the letter becomes possible tomorrow)

You can park in any parking spot if you become a club member=> This person definitely knows how to park a car. What is emphasized is that he or she will be allowed to park in any parking spot if he or she becomes a club member (parking in any parking spot becomes possible after he or she becomes a member)