'I'm' is the contraction of 'I am'. While 'am' is a primary auxiliary verb 'to be' like: is, are, was, were, am, be, being, and been. These auxiliary verbs could be used as helping verbs e.g. I am eating she is reading They are also used as linking verbs e.g. I am a teacher The difference between I'm and am is: I'm is the first person singular pronoun I and auxiliary verb am while 'am' is just an auxiliary verb that can't start a sentence. OR Difference between I am and am I? I am is used to make a statement, like "I am a teacher", or "I am a member of the book club". Am I is usually used for: 1. Questioning. "Am I supposed to be here tomorrow?" 2. Challenging (expressing disbelief) a statement. "You are very beautiful." "Am I?" 3. Rhetoric sentence. "Wow, I am a good mentor, am I now?"