Can vs. Able To
'Can' and 'be able to' are both used to refer to abilities. In this lesson, we will learn their differences and when to use them.
What Is Their Main Difference?
'Can' and 'be able to' are both used to show ability but the main difference between them is in their parts of speech. 'Can' is a modal verb and 'be able to' is a phrasal verb.
Modal Verb Can
'Can' is one of the most commonly known modal verbs (also known as modals or modal auxiliary verbs) used to talk about possibilities, ask for or give permissions, request something, etc. We use can to refer to the present and the future. Have a look:
I
I
Be able to
'Be able to' is a verb phrase. We use 'be able to' to talk about abilities. The presence of the auxiliary verb 'be' allows us to use the phrase in both present and past tense.
He
He
Similarities
Talking about Abilities
We use 'can' and 'be able to' to talk about abilities, knowledge, or talent. We use 'can' to talk about the present and the future. 'Be able to' is used in all tenses to show ability. For example:
I
I
I
I
Negation
When we want to make v sentences, we use 'cannot' and 'not able to' or 'unable to.' For instance:
I
I
I
Differences
Parts of Speech
'Can' is a modal verb that is used to give additional information about the function of the main verb. Have a look:
I
They
'Be able to' is a phrasal verb. A phrasal verb is a phrase that functions as a verb. Take a look at the following example:
I
They
With Modals
'Can' is a modal verb and we cannot use two modals in one sentence at once. In this case, we use 'to be verb' since we can use it with other modals. Have a look:
I should can work with a broken keyboard.
I
With Tenses
We use 'can' and 'be able to' with tenses:
Past Tense
We cannot use 'can' itself to talk about the past. Instead, we use 'could.' With 'be able to,' we use the past tense of the auxiliary verb 'be': was/were. Take a look at the following example:
I can run fast when I was younger. → I
I
Present Tense
We can use both 'can' and 'be able to' to talk about present abilities. 'Can' is more common than 'be able to.' Here are some examples:
Harry
Harry
Future Tense
We use 'be able to' to talk about a future skill to have in the future. These skills are not available right now and will only be achieved in the future. For example:
I
I can see again after the operation.
Here, we are talking about the present rather than the future.
We use both 'can' and 'be able to' to talk about decisions for the future and future arrangements. Have a look:
I
I
Questions
Both 'can' and 'be able to' are used to make questions.
'Can' is simply inverted to create questions. Watch:
I
You
To make a question with 'be able to,' we invert the 'be' and do not change the position of 'able to.' Consider the following examples:
He