'didn't' is a contraction that combines the auxiliary verb 'did' with the negation 'not.' It's used to form the negative of the past simple tense. The contraction serves to make speech and writing more concise and is often used in informal contexts.
used for forming the negative of the past simple tense, asking negative questions in the past simple tense, and emphasizing a negative statement in the past.
I didn't see that coming.
Didn't you hear the alarm ringing?
She didn't want to join us for dinner.
While 'didn't' is common in informal speech and writing, in more formal contexts, you might opt for 'did not.' As with 'did not,' be cautious about double negatives. Since 'didn't' already provides negation, the main verb should be in its base form without any other negatives. For instance, 'She didn't go' is correct, while 'She didn't not go' is incorrect.
In questions, the subject follows 'didn't.' For example, 'Didn't she go to the party?' 'Didn't' is specific to the past simple tense. It's not used with other tenses. A common mistake is using 'didn't' with the past form of the main verb. The correct form is 'didn't' + base form of the verb. For example, 'I didn't go' is correct, while 'I didn't went' is incorrect.