Both 내가 and 제가 mean "I am" but 내가 is used to those who are the same age as you or are younger 제가 is honorific to 내가, which is used to groups older than you or to express respect for someone. ex) Can I ~~~~ 내가 Could I ~~~~ 제가

Long and useful answer I got there.Thank you very much RobJ.There is so much to learn.For your information, I'm self taught because there's few to non Korean teacher from where I am.The only fastest way to get going is through here or other website even youtube. I'll take baby steps. 감사합니다.

Yes, 제가 is more formal and 내가 less formal (but in my opinion, still formal enough for Korean learners in most cases), but... Have you studied enough to notice the subject markers 은/는 and 이/가? And are you aware of 저 and 나? Both are ways to refer to yourself, 저 being the more formal one and 나 being the less formal one. Well if you were to use 저 and 나 with 은/는, you'd have to use the ~는 and you'd get 저는 and 나는. BUT, if you were to use 저 and 나 with 이/가, you'd have to use the ~가, but you wouldn't say 저가 or 나가, for whatever reason these would change to 제가 (저 + ㅣ + 가) and 내가 (나 + ㅣ + 가). Hope that makes sense! Rob... p.s. They don't actually mean "I am", they just mean "I". It'll depend on what type of verb comes after to determine whether the "am" part will be there. For example, both of these subject pronouns could be part of the sentence, "I eat" or "I play".