Why “Couldn’t Able to” is Incorrect and What You Should Say Instead

Common English Errors: When you talk about a situation in the past when you tried harder to achieve something and succeeded in it, then you usually use ‘was able to’ or ‘managed to’.

Whenever I read comments on Facebook posts on the newsfeed, I cringe at the silly errors they commit. With the growing internet consumption, people actually grow up reading blogs that are teeming with grammar errors.

One of those glaring examples is “couldn’t able to”.
For Example:

I couldn’t able to sleep last night.
So what’s wrong with the example above?

Let me explain…

To understand the use of ‘could’, one needs to understand the rules of ‘modal verbs’ in English.

Here’s the deal.

Both can and be able to can be used to explain the ability of a person, especially when they try to do something.

For Example:

I can answer that question = I am able to answer that question (sounds a little formal)
Similarly, here are some examples in which the speaker is talking about his/her ability in the past.
I could walk much faster when I was 15 = I was able to walk much faster when I was 15.

Moreover, when you talk about a situation in the past when you tried harder to achieve something and succeeded in it, then you usually use ‘was able to’ or ‘managed to’.

For Example:

The test was very tough; I was able to answer only four out of ten questions. (the speaker tried his/her best and could do only four)

The test was very tough; I managed to answer only four out of ten questions. (managed to = was able to)

Note that you can also use the following sentence:

The test was very tough; I couldn’t do more than four out of the ten questions.

If you are wondering if you could use ‘I could do only four out of ten questions, then the answer is you can but it will explain the situation clearly enough.

In fact, this is the reason why they use ‘managed to’ or ‘was able to’ – it clearly says something was difficult.

Here are some more examples:

I managed to book three tickets for the show. (the speaker indicates difficulty)
She was able to clear the test on her fourth attempt. (the test must have been tough)

Now that the rules are clear to you, take a look at the sentence below:

I couldn’t able to sleep last night.

So, what’s wrong?

Sure, the speaker has mixed up two things here: couldn’t and able to whereas he should have used just one, for example:

Either: I couldn’t sleep last night. (they were partying hard in the neighborhood)

Or: I wasn’t able to sleep last night.

The next time you notice something writing ‘can’t able to’ or couldn’t able to, just share this link with them.

More Resources: Learning English with BBC

Reader Interactions

2 Reactions