We use many and a lot of in all types of sentences (positive/negative/question): We have many friends / a lot of friends. We don't have many friends / a lot of friends. Do you have many friends / a lot of friends?

'Many' and 'a lot of' with plural countable nouns:

• Both 'many' and 'a lot of' can be used in positive, negative, and question sentences with plural countable nouns.
• 'A lot of' is generally more common in informal positive statements.

Examples:

• We have many friends / a lot of friends. (Positive)
• We don't have many friends / a lot of friends. (Negative)
• Do you have many friends / a lot of friends? (Question)