hello is used as an interjection to greet someone, as a sign of recognition or acknowledgment. It is often used at the beginning of a conversation to draw someone’s attention or start a dialogue.
1. 'Hello, how are you?'
2. 'Hello, it's so nice to see you!'
3. 'Tom! Hello!'
When used as an interjection at the beginning of a conversation, hello is usually followed by a period, an exclamation point, or a question mark to indicate the context of the expression.