Can you override an abstract method as virtual?

Short answer: No, abstract methods must be overridden with override in derived classes. You can then mark the overriding method as virtual to allow further overriding in subclasses. abstract class Vehicle { public abstract void Start(); } class Car : Vehicle { public override void Start() => Console.WriteLine("Car starts"); }

Real-world example (ShopNest)

ShopNest has a base PaymentMethod with virtual decimal Fee(). UpiPayment and CardPayment override the fee logic without changing the checkout caller.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.