When you want to comment on a video, think about what you liked or didn't like, and say that. You can also ask a question if something made you curious or you want to know more. If the video made you laugh or think, you can share that feeling. It's nice to be kind and positive in your comments. If you didn't like the video, it's okay to say so, but try to say it in a way that's helpful and not mean. For example, you could say, "I really liked how you explained this part, it made it easy to understand," or "I was hoping to learn more about this topic, could you cover that in a future video?"