الأستاذ شرح جيداً

You can say this directly to a classmate after a lecture. You can also use it to tell your parents how school went. It is very common in Egyptian Arabic. Just swap الأستاذ for الأستاذة (Al-ustadha) if the teacher is a woman. It is a very versatile and friendly sentence.

Use it when you finally understand a complex math problem. Use it when a history lecture felt like a fun story. It is perfect for texting a friend who missed class. You can also use it in a course evaluation. It shows appreciation for the teacher's hard work. It makes you sound like a dedicated student.

Do not use this if the teacher is standing right there. It might sound a bit too casual or like you are 'grading' them. In very formal Modern Standard Arabic settings, use جيداً instead of كويس. Avoid it if the explanation was actually confusing. Using it sarcastically might be misunderstood by others. Keep it for genuine moments of clarity.

In Arab culture, teachers are highly respected figures. There is a famous saying: 'The teacher is almost a prophet.' Praising their ability to explain is a sign of high regard. The word كويس is the heartbeat of Egyptian dialect. It comes from the word for 'garment' or 'well-made.' It suggests something is of high quality and pleasing.

You might hear المدرس شرحه حلو (The teacher's explanation is sweet). Or فهمت منه كويس (I understood well from him). In the Gulf, they might say الشرح كان زين. In the Levant, they often say الأستاذ شرحه منيح. All of these share the same warm, appreciative sentiment.