Hello is what you say when you greet someone or answer the phone. It's the most common way to start a conversation in English, whether you're meeting a friend at school, answering a call from your grandparents, or introducing yourself to someone new.

The word works in almost any situation: casual or formal, with strangers or close friends. You might say a cheerful “Hello!” to your teacher in the morning, or answer the phone with a questioning “Hello?” when you don't know who's calling.

You can also use hello to get someone's attention when they seem distracted: “Hello? Are you even listening to me?” And when something seems obvious, people sometimes say “Hello!” with emphasis, meaning “Wake up and notice what's right in front of you!”