What is a word we use to ask questions when we want to find out information about something. When you ask “What is that strange noise?” you're trying to identify or learn about something you don't know yet. When you ask “What happened?” you want someone to explain events you missed.

What is one of the most useful words in English because it opens the door to learning. Scientists ask “What causes lightning?” Detectives ask “What happened at the crime scene?” Students ask “What does this word mean?” Each what question seeks to uncover information, understand something better, or solve a mystery.

The word also appears in many common phrases. When someone says “What if we tried a different approach?” they're suggesting a possibility. When they exclaim “What a beautiful sunset!” they're expressing amazement or a strong feeling. And when someone says “So what?” they're challenging whether something really matters.

Sometimes what expresses confusion or surprise, like when you can't believe what you just heard: “What? You're moving to Alaska?” In this way, a simple what can be an entire sentence that means “I didn't hear you clearly” or “That's so surprising I need you to repeat it.”