"I know many famous people."
Translation:Yo conozco a muchas personas famosas.
gente is a feminine singular noun ===> conozco [a] mucha gente famosa
Famous people have no connection to me, I have no feelings towards them so why should the ‘a’ be needed? Translation check did NOT use the A.
If you have just said that you know them, they have a connection to you.
Saber is to know how or know about an impersonal subject. Conocer is to know or meet a person or a place.
I took the sentence to mean I know of or about many famous people, not that I have personally met them, that is why I used sé.
gente is used for people as a whole, as a group and not individuals...