Definition:
'doesn't' is a contraction that combines the auxiliary verb 'does' with the negation 'not.' It's used to form the negative of the base form of main verbs in the third person singular of the present simple tense. The contraction serves to make speech and writing more concise and is often used in informal contexts.
Rules:
used for forming the negative of the third person singular in the present simple tense, and asking negative questions in the third person singular of the present simple tense.
Examples:
He doesn't like chocolate.
She doesn't go to the gym on weekends.
It doesn't rain much in the desert.
Tips:
while 'doesn't' is common in informal speech and writing, in more formal contexts, you might opt for 'does not.' As with 'does not,' be cautious about double negatives. Since 'doesn't' already provides negation, the main verb should be in its base form without any other negatives. For instance, 'She doesn't like' is correct, while 'She doesn't not like' is incorrect. In questions, the subject follows 'doesn't.' For example, 'Doesn't she like chocolate?' 'Doesn't' is specific to the third person singular of the present simple tense. It's not used with other tenses or persons. A common mistake is using 'doesn't' with the third person singular of the verb 'to be.' The correct form is 'is not' or its contraction 'isn't.'