A DVSA-approved driving instructor (ADI) has passed a three-part qualification and is on the official register. A potential driving instructor (PDI) is still training and displays a pink badge; they must be registered and sponsored. Both can be excellent — ask how many hours they have taught and what their standards check grade is if they are a qualified ADI.
You should be able to see a badge in the windscreen while you are being taught. Check the register rather than taking a social post at face value.
Questions that save money
What transmission? Which test centre do you use? How do you decide I am ready? What happens if you cancel? Do you charge for the test-day hire of the car? PassNear listings are profiles, not bookings — you contact the instructor directly, and nobody here takes a cut of your lesson fee.