Of course

You can use it at the start of a sentence or as a standalone answer. If someone asks for a favor, it shows you are happy to do it. If you are stating a fact, it adds emphasis. It is like adding a bright highlighter to your agreement. Just be careful with your tone of voice! If you say it too sharply, it might sound like you think the question was silly.

Use it when you want to be polite and helpful. It works great at a restaurant when you ask for more water. The waiter says, Of course, to make you feel welcome. Use it with friends when they invite you to a party. It shows you are excited to go. It is also perfect for confirming facts that everyone knows, like Of course it rains in London!

Avoid using it if someone is sharing a new or surprising secret. If they say, "I'm getting married!" and you say Of course, it sounds like you aren't surprised at all. That might hurt their feelings. Also, don't use it if you are actually unsure. If your boss asks if a project will be done by Friday and you aren't certain, stick to I think so instead.

English speakers love to sound helpful and agreeable. Of course became popular because it sounds more sophisticated than just saying yeah. It comes from the idea of following a 'course' or a natural path. In the UK and the US, it is a social lubricant. It makes conversations move smoothly and helps people feel like they are on the same team.

You will often hear Of course not for a strong 'no'. In very casual settings, people might just say Sure or Definitely. In a professional email, you might see Certainly. But Of course remains the king of everyday certainty. It is the perfect middle ground for almost any situation you find yourself in.