English Language Clinic -UI

‘DOES,’ ‘DID,’ ‘DO’ IN QUESTIONS

When 'does', 'do', or 'did' is used to ask a question, the main verb should be in the base form without any inflections. Therefore, it is correct to say 'Does your father work for an oil company?' and incorrect to say 'Does your father works for an oil company?'
Although 'father' is singular, the main verb in the sentence above should not include 's'.

In the expression 'Does your father work for an oil company?', the main verb 'work' is in its base form, which might seem like it should be plural. However, the reason it appears as 'work' (the base form of the verb) is due to the auxiliary verb 'does.'

When using the auxiliary verb 'does' (which is singular, for third-person singular subjects like 'he', 'she', 'it', or in this case, 'your father'), the main verb that follows must be in its base form. So, even though 'work' looks like its base form, the singular nature of the subject ('your father') is reflected in the auxiliary verb 'does', which is why the overall construction is considered singular. The main reason the construction is singular is because of the singular subject-verb agreement demonstrated through the use of 'does'.