The document discusses different types of interjections used to express emotions. It provides examples of interjections used to express warmth in greetings like "Hello" and "Hey". Interjections used to show happiness over good events include "Hurrah" and "Wow". Interjections for surprise are "Ha" and "Oh". Finally, interjections for grief or pain over unfortunate events include "Alas" and "Ouch".