“I didn’t do anything” is correct in standard English grammar. In many parts of the English-speaking world, people say ”I didn’t do nothing”.
When you have a negative sentence(did not in this case), you need to use “anything”. “Nothing” is a word that you can use to make a sentence negative so there is no need to use “did not”.
I didn’t do anything (meaning and usage)
We often use” I didn’t do anything” in the context of excusing ourselves from doing something wrong.
Who stole the glass?
It wasn’t me, I didn’t do anything.
I didn’t do nothing (meaning and usage)
I didn’t do nothing is a double negative.
Double negatives can often have a positive meaning but this is not the case in this situation.
When people say “I didn’t do nothing” they mean that they didn’t do anything wrong.
Nothing is a negative word so you only need to say:
I did nothing.
Many people argue around the world that “I didn’t do nothing” is uneducated and incorrect. It is incorrect grammar but this phrase is common around the English-speaking world and I don’t think people should be judged or labeled “uneducated”.
We all have different ways of speaking and there is no one way that is correct.
An English exam/Job Interview
If you are taking an exam or doing a job interview, it is best to use “I didn’t do anything”.
In an English exam, you will receive fewer points as it is incorrect grammar and during a job interview, you are being judged on your ability to communicate among other things.
Is the sentence “I didn’t do nothing” correct?
“I didn’t do nothing” is grammatically incorrect but common non-standard English. This means that it is common around the English-speaking world even though it is incorrect.
Did nothing or did not do anything?
“Did nothing” and “did not do anything” have the same meaning.
There was a fire in the house but she did nothing.
There was a fire in the house but she didn’t do anything.
Both sentences have the same meaning.