1. 'I'm' is an abbreviation for the word 'I AM.' It is used in combination with other words to tell someone about yourself or to describe something you are doing.Examples:
"I'm so tired."
"I'm happy."
"I'm twenty three years old."

2. You can also add descriptive words with 'I'm' such as.Examples:
"I'm extremely tired."
"I'm very happy."