How to explain, 'He lives in London.' but 'Where does he live?'

[Kawkabwaheed]

Greetings:
I am helping a student learn English but I am having trouble explaining some grammar to him.
In the sentence, “He lives in Britain.”, he understand that the third person singular verb always has an “-s” or “-es” attached to it. However, he (and I) don’t understand the following.
Why does “live” lose the “s” in the sentences “Where does he live?” or “Does he live in Britain or France?”. Similarly, “-s” in “He drives cars.” but no “-s” on the verb “drive” in “Does he drive a car?”
Also, the sentence “He fixes cars.” is easy to understand but why does the verb “fix” loses its “-es” in the negative sentence “He does not fix cars.”
Any advice anyone can give us in this matter is greatly appreciated.

[Alan]

Hi,

In the present simple tense we make the negative form and the interrogative form by using the appropriate part of the verb 'do' + the infinitive of the verb in question.

This why the question (interrogative) form becomes: Does he live (infinitive)? and the negative form becomes: He doesn't live (infinitive).

The same construction follows with the past simple: Did he live (infinitive)? and He didn't live (infinitive).

I hope that helps.

Alan
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English as a Second Language
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[Kawkabwaheed]

How to explain, “He lives in London.” but “Where does he live?”?

[Florawong]

it is grammatical rules. you just have to remember that. when it is changed into interrogative form or negative form, we need to use auxiliary verbs do, and we change "do" into does to indicate the tense. Therefore the notional verbs "ive" remain it original form.