The gift of (the) gab British American noun phrase informal
It can use in posivtive or negative situation.
The ability to converse confidently and easily in a way that makes people pay attention to you and believe you.
He has got the gift of gab which is essential to do in sales.
I don't argue with him because of his gift of gab.
She has got the gift of gab, so she should become a lawyer.
This expression originates from the word 'gob' in Middle English, meaning mouth, and 'gabbe' meaning idle speech.
To tell someone the truth about something that they had not understood or received false information
I have to set my wife straight about what happened yesterday.