Modals – Can, Could & Be Able To

In this video, we dive deep into the differences and uses of Modals – Can, Could, & Be Able To in English grammar. You’ll learn how to express ability, possibility, and permission effectively with these modals. We’ll cover real-life examples to help you understand when and how to use each one, including both present and past forms. Whether you’re learning English or refining your grammar, this video will make understanding modals much easier. Don’t forget to like, comment, and subscribe for more grammar lessons!

Grammar

Practice how to use Can, Could & Be Able To.

Transcript

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Introduction:

• Host: Hello and welcome to the English Magnet. Today’s video: Can, Could & Be Able to Made Easy! Ever wondered why everyone keeps saying “can” all the time? It’s one of those words that we constantly use without thinking much about it. Don’t worry if you’ve never really thought about it before because by the end of this video, you’ll have a clear understanding of how to use “can” for ability, permission, and even possibility, its past version ‘could’ and future form ‘be able to’. Let’s break it down and dive into one of the most useful words in English!

Part 1: Can / Can’t

Can / Can’t

“Can” is a modal verb used to express ability, permission, or possibility in the present or near future. “Can’t” is the negative form of “can,” indicating the inability or impossibility of something. A modal verb accompanies a base form of a verb to give it context as to how likely it is or whether it’s allowed for instance. To put it simply, “can” is followed by a base form. 

Let’s look at the structure:

Structure:

• Affirmative: Subject + can + base form of the verb.
• Negative: Subject + can’t + base form of the verb. (can’t or cannot on screen) 
• Question: Can + subject + base form of the verb? / Can’t + subject + base form of the verb?

As you can see ‘can/can’t’ is followed by a base form, that’s always the case. Obviously due to the inversion in a question the subject nudges itself between the modal verb and the base form of the verb. 

Now let’s cover the different meanings of ‘can’: 

• Ability:
  • I can swim. (I have the ability to swim.)
  • She can’t drive a car. (She does not have the ability to drive.)

By now you know that can or can’t never takes an ‘s’ with he/she/it. Moreover, the base form also remains unchanged. (she can’t is highlighted)

• Permission:
  • You can borrow my bike. (Permission is given.)
  • You can’t go outside after 10 pm. (Permission is denied.)
  • Can I use the bathroom? (Asking for permission) 

By the way, some people prefer ‘May I use the bathroom?’ when someone asks for such permission. However, with ‘can’ it’s totally fine as well. Feel free to enlighten people who might not know about that 🙂 

• Possibility:
  • It can rain tomorrow. (There is a possibility that it will rain.)
  • This can’t be true! (It is impossible for this to be true.)

Part 2: Could / Couldn’t

“Could” is used to express past ability, past permission, polite requests, or hypothetical situations. “Couldn’t” is its negative form (or could not). In short, it’s the past form of ‘can’ and a bit more!

Let’s look at the structure:

Structure:

• Affirmative: Subject + could + base form of the verb.
• Negative: Subject + couldn’t + base form of the verb.
• Question: Could + subject + base form of the verb? / Couldn’t + subject + base form of the verb?

The structure is basically a copy/paste of the sentence structure with ‘can’ but plugging ‘could’ instead.

Now let’s cover the different meanings of ‘could’: 

• Past Ability:
  • When I was a child, I could run fast. (I had this ability in the past.)
  • She couldn’t play the piano when she was young. (She didn’t have the ability in the past.)

As seen in the examples, the base form isn’t in the past (run and play are highlighted) because ‘could’ already places the timeframe in the past. 

• Past Permission:
  • When I was a teenager, I could stay up late on weekends.(I was allowed to stay up late)
  • In school, we could go to the library whenever we wanted. (again, going to the library was allowed when the group was in school)

Here ‘could’ works fine for past permission, but it is less commonly used. It’s more precise to use ‘was/were allowed to’. 

• When I was a teenager, I was allowed to stay up late on weekends.
• In school, we were allowed to go to the library whenever we wanted.

By using ‘was/were allowed to’ clearly speaks of past permission while the ‘could’ form might not convey past permission but rather past ability although it’s still correct. 

• Polite Request or possibility:
  • Could you help me with this task? (Polite present request, more formal than ‘can’)
  • Couldn’t you stay a little longer? (Polite present suggestion)
  • Mike could be in class at the moment. (Present possibility)
  • It could rain in the evening. (Future possibility)

In the first two examples, ‘could / couldn’t’ aren’t linked to the past. It’s a more polite form than ‘can’ when expressing a request or suggestion. While in the last two examples it hints at a present or future possibility. Maybe Mike is in class, or maybe not. Maybe it will rain, or maybe it won’t. We are not dealing with ability or permission and absolutely not in the past! It’s all about context!

• Hypothetical Possibility:
  • If I had more time, I could travel the world. (Hypothetical possibility.)
  • It couldn’t have been John who broke the vase. (Impossibility in a past hypothetical situation.)

To keep it brief, ‘could’ emphasizes that something is possible but depends on certain conditions, if it’s followed by a base form you’re dealing with a present or future possibility (could travel is highlighted), while when followed by have + past participle you’re dealing with a past possibility. (‘couldn’t have been’ is highlighted). 

Part 3: Be Able To

Right off the bat, ‘be able to’ is not a modal verb. It’s included here for consistency; it represents the future form of ‘can’; there is no such thing as ‘will can’. So, it’s a versatile phrase used to express ability, and it often works in situations where “can” cannot be used because of tense restrictions (especially in the future) and in certain cases it can even be used in the past and present. 

Anyhow, first the structure:

• Affirmative: Subject + be able to + base form of the verb.
• Negative: Subject + be not able to + base form of the verb. (it’s ok to use a contraction with ‘be’ here; wasn’t, weren’t, aren’t, isn’t, won’t be) 
• Question: Be + subject + able to + base form of the verb? / Be not + subject + able to + base form of the verb?

Just note that ‘be’ needs to be conjugated in the correct tense. (was, were, am, are, is, will be) 

With that being clear, let’s now cover the different meanings of ‘be able to’: 

• Future Ability:
  • I will be able to drive once I pass my driving test. (In the future, I’ll have the ability to drive.)
  • After the repairs are done, we will be able to use the washing machine again. (In the future, the washing machine will be functional.)

When used in the future tense (will be able to), you are simply expressing a future ability; it’s ‘can’ in the future. Pretty straightforward so far! 

• Present Ability:
  • She is able to speak three languages fluently. (Formal way to express present ability.)
  • They are able to complete the task in record time. (This sentence focuses on the ability of ‘they’ to do a task very well.)

When using in the present tense (am/are/is able to), you are simply expressing a present ability in a more formal way than ‘can’. So, both forms are basically interchangeable. 

• She can speak three languages fluently. 
• They can complete the task in record time. 

‘Be able to’ in the present is pretty clear, right! 

• Past Ability:

You already know that ‘could’ is used to express a past ability, so perhaps ‘was/were able to’ is interchangeable with ‘could’… Unfortunately here there’s a twist. Here’s the key nuance:  ‘could’ talks about general ability in the past, but ‘was/were able to’ is used to emphasize someone’s success or ability to do something in a specific situation.

• She was able to solve the puzzle in record time. (Here we emphasize the success of solving the puzzle.)
• He was able to escape before the building collapsed. (The fact that he managed to escape at a specific moment isn’t about his general ability to leave a building.) 

Even though ‘be able to’ is the only way to express a future ability, don’t dismiss it in the present when you want to be more formal and in the past when focusing on achievement or a single instance. 

Wrap up: There we go! Can, could and be able to cover abilities across tenses and even more! Were you able to form sentences about abilities prior to this video? If not, surely by now you can! 🙂 Hopefully, this has been helpful. A link to some free material to practice by yourselves can be found in the description below. Keep practicing, and you’ll get the hang of it. Thank you for watching. Until next time!