[Idiom] the Gift of Gab

the gift of the gab ( UK) /the gift of gab (US)

meaning:

the ability to speak easily and confidently in a way that makes people want to listen to you and believe you
 

Gab , dating from the late 18th century, was an informal word for ‘conversation or chatter’
 

Example:

She's got the gift of the gab - she should work in sales and marketing.