Hi !!
9) where your father / live
Where does your father live ?
10) what/ sell / Max
What does Mark sell ?
(Do,Does)
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in the interrogative or negative form, the 's' of the 3rd p. singular is added to the auxiliary "do"
<em>Where do you live ?</em>
<em>I live in New York.</em>
<em>Where does he lives?</em>
<em>He lives in LA.</em>
<em />
<em>DO </em><em>takes the 's' of the 3rd p. singular, and the verb stays as a verb in base form. </em>
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hope this helps:)
