Hello & Hi

1. Hi :

Example :

Hi, Edward. How are you ?

Use :

Context :  Informal

Purpose : to greet people who you know such as friends.

2. Hello :

Example :

Hello, can I see Mr Edward ?

Use :

Context : formal and more polite

Purpose : to greet people especially those you don’t know or meet for the first time or to whom you should show respect because of age or work hierarchy