Can abstract classes implement interfaces?

Short answer: Yes, abstract classes can implement interfaces partially or fully. Derived classes must implement any remaining abstract members. interface IDriveable { void Drive(); } abstract class Vehicle : IDriveable { public abstract void Drive(); }

Example code

class Car : Vehicle { public override void Drive() => Console.WriteLine("Car drives"); }

Real-world example (ShopNest)

Checkout calls IPaymentGateway.Charge(). Razorpay and Stripe adapters implement the same interface, so ShopNest can switch gateways without rewriting the order service.

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.