How to Use Can, Could and Be Able To - English Modal Verbs for Ability

Summary

This lesson focuses on using modal verbs like 'can' and 'could' to express ability in English. It explains when to use 'can' for present or future abilities and 'could' for past general abilities. The video also covers the use of 'be able to' and 'managed to' when modal verbs aren't suitable, particularly in specific past situations or with certain tenses. Additionally, it clarifies how 'could' can express both past abilities and hypothetical situations. Overall, the lesson helps learners understand when and how to use these verbs to talk about abilities in different contexts.

Takeaways

• 😀 You can use 'can' and 'could' to talk about abilities in the present, past, and future.
• 😀 'Can' is used for present and future abilities, while 'could' refers to general past abilities.
• 😀 'Be able to' is a non-modal verb that can be used in place of 'can' or 'could' in certain tenses.
• 😀 In the present perfect tense, 'can' and 'could' are not used, so 'be able to' is necessary.
• 😀 After verbs like 'like', you need to use 'be able to' instead of 'can' or 'could' (e.g., 'I like being able to choose my working hours').
• 😀 When talking about a specific ability in the past, use 'be able to' or 'managed to', not 'could'.
• 😀 In negative sentences, there is no difference between using 'couldn't' and 'weren't able to'.
• 😀 'Could' can have two meanings: a past ability or a hypothetical meaning depending on context.
• 😀 Use 'be able to' in all situations if you're unsure, as it's always correct.
• 😀 If the sentence is talking about a specific past event and is positive, you must use 'be able to' or 'managed to' instead of 'could'.

Q & A

What are modal verbs, and why are they important?

Modal verbs are auxiliary verbs used to express possibility, necessity, ability, permission, or obligation. They are important because they help convey nuances of meaning in a sentence, such as the difference between ability, permission, or hypothetical situations.

How do 'can' and 'could' differ when talking about ability?

'Can' is used to talk about present or future abilities, while 'could' is used to talk about abilities in the past. For example, 'She can speak Spanish' (present) vs 'She could speak Spanish when she was younger' (past).

When is it necessary to use 'be able to' instead of 'can' or 'could'?

'Be able to' is used when 'can' or 'could' cannot be used, especially in certain verb tenses like the present perfect or when following verbs like 'like' that require an '-ing' form. For example, 'He has been able to swim since he was two' (present perfect).

Can 'can' and 'be able to' always be used interchangeably?

In most cases, 'can' and 'be able to' have the same meaning and can be used interchangeably. However, 'be able to' is preferred in more formal contexts or when using specific tenses where 'can' and 'could' don't exist, like the present perfect.

What is the difference between 'could' and 'be able to' when talking about specific past situations?

When discussing specific past situations, 'could' is not used. Instead, 'be able to' or 'managed to' should be used. For example, 'We were able to catch the train' or 'We managed to catch the train' refers to a specific moment in the past, whereas 'could' would be incorrect.

How do you use 'could' to talk about hypothetical situations?

'Could' can express hypothetical or conditional ability. For example, 'We could work together if you wanted to' uses 'could' to indicate a hypothetical scenario, meaning the ability exists only under certain conditions.

What happens when the sentence is negative? Can 'could' and 'be able to' be used interchangeably?

In negative sentences, there is no difference between 'could' and 'be able to'. Both forms are used to express inability, and either can be used without changing the meaning. For example, 'We couldn't finish everything' or 'We weren't able to finish everything' both convey the same idea.

Why can't 'can' and 'could' be used in the present perfect tense?

'Can' and 'could' do not have a present perfect form, which is why 'be able to' is required in sentences that need the present perfect tense. For example, 'He's been able to swim since he was two' cannot use 'can' or 'could' in this context.

What should you use if you're not sure whether to use 'can' or 'be able to'?

If you're unsure, it's safe to use 'be able to'. It is always correct and can be used in every case where 'can' or 'could' might be used, especially in tenses where 'can' and 'could' are not possible.

What are the two different meanings of 'could'?

'Could' can have a past meaning, as in 'I could run fast when I was younger', or a hypothetical meaning, as in 'I could help you if I wanted to'. The meaning depends on the context and whether the sentence is talking about past ability or a conditional situation.