What does it mean? vs What does it means?

English as a Second Language English Vocabulary, Grammar and Idioms
1

Hi,

could anyone please tell me which one out of the following two sentences are correct interrogative sentence

1)What does it mean? 2)What does it means?

Can I use s behind the verb ‘mean’ or not?

2

Only the first question is correct.[YSaerTTEW443543]

TOEIC listening, photographs: Preparation for a meeting[YSaerTTEW443543]

3

Hi,
why the first one is correct, not second?
we can use s behind verb in simple present for the third singular person, then why is that so?

4

True, we can and we should, but when an auxiliary verb is being used (Does) the rule has being already applied, therefore the main verb remains in its base form.