The short answer
English verbs have exactly one modal slot. Both can and be able to fill that same slot — they mean the same thing. Using both at once is like saying “will shall go” — grammatically impossible.
Wrong vs. Right
Wrong
I can able to speak English.
Right
I can speak English.
Use 'can' alone for present ability.
Wrong
She can able to solve it.
Right
She is able to solve it.
Use 'be able to' alone as an alternative.
Wrong
He cannot able to come.
Right
He cannot come. / He is not able to come.
Negation works with either — not both.
Wrong
Will you can able to help?
Right
Will you be able to help?
After another modal (will), use 'be able to'.
The Real Reason This Happens
In Hindi and Urdu, ability is often expressed with a construction that translates word-for-word as “can + able to” (kar sakta hoon + a literal “able” equivalent). When learners translate this structure directly into English, “can able to” is the result.
The fix is to treat can and be able to as synonyms that occupy the same slot — pick one, drop the other.
When to Use Which
| Situation | Use | Example |
|---|---|---|
| Present ability (simple) | can | I can swim. |
| After another modal | be able to | I will be able to come. |
| In perfect tenses | be able to | She has been able to manage. |
| Past ability (achieved) | was/were able to | He was able to escape. |
| Past ability (general) | could | She could run fast as a child. |
Exam tip
In SSC CGL and CHSL error-spotting, if you see can/could/will/shall/may/might followed by be able to, it is always an error. Circle it and move on — no exceptions.
Frequently Asked Questions
Why is 'can able to' wrong?+
'Can able to' is wrong because English allows only one modal expression per verb phrase. 'Can' is a modal verb. 'Be able to' is also a modal expression. Using both together — 'can able to' — is called a double modal error. You must choose one: either 'can do it' or 'is able to do it'.
What is the correct form — 'can do' or 'is able to do'?+
Both are correct — use one, not both. 'She can do it' and 'She is able to do it' mean the same thing. 'Can' is used for present ability. 'Be able to' is more formal and can be used in all tenses: 'She was able to finish', 'She will be able to come'. Never say 'She can able to do it'.
What is a double modal error?+
A double modal error happens when two modal expressions appear in the same verb phrase. English allows only one modal per verb phrase. Common double modal errors: 'can able to', 'must should', 'would can'. The fix is always to keep only one: 'can do it', 'should do it', 'would do it'.