Hello Jaycee! The answer of Alex is very well explained. "Yo" is the first personal pronoun ( "I" in English) and is the most easy to understand and use. You should note that in Spanish, that pronoun is usually omitted in some contexts. For example, when somebody asks you "Where're you from?" ( "De dónde eres?") it's common to answer: "Soy de Argentina", instead of "Yo soy de Argentina", both mean the same ( I am from Argentina) but if you say "Yo" at the beggining, it sounds weird. "Me" can be used in different forms. The Reflexive Pronouns are Personal Pronouns that complement the reflexive verbs, and agree in person and number with the subject of the sentence. The reflexive pronouns always refer to the subject, indicating that the action that the subject performs falls on him/her at the same time. For example: "Me miro en el espejo" ("I look at myself in the mirror" = I'm looking at the mirror, and I look to myself at the same time. I am the one who performs the action, and the action of the verb falls on myself ) Here "me" is the Reflexive Pronoun. If I say: " Me gusta mirarme en el espejo", that means "I like to look at myself in the mirror". In this case, "mirarme" is the Reflexive Verb ( means "mirarme a mi misma"= look at myself) These are simple examples in the first person, although grammatically both Reflexive Pronouns and Reflexive Verbs have other uses and more complex forms. "Mi" is a Possessive, like when you say "my" in English. They indicate possession or ownership. They always agree in gender and number with the noun they refer to; that is, with the possessed thing. If the possessive appears next to the noun that designates the element with which a relationship of belonging is established, then it is called a Possessive Determinant. If the noun is omitted, then it is a Possessive Pronoun. For example: "Ese es mi libro" = "That is my book", if you're talking about 2 or more books, you must say " Esos son mis libros" (plural).

Interesting question. I am learning Spanish and I find this question and the answers are useful. Thanks a lot!!!

Alex's and Sofía's answer's are both excellent. The words "yo", "me" and "mi" are all first-person singular pronouns that are used in different ways. However, there is one more first-person singular pronoun that you did not include in your list; maybe you haven't learned about it yet. The other pronoun is "mí", and it is used only after a preposition. The presence or the absence of the accent mark in writing is the only thing that distinguishes "mi" (the possessive adjective) from "mí" (the object of a preposition).

“Yo” is a subject pronoun, it indicates it’s “I” doing the action. For example: I read a lot - Yo leo mucho. “Me” is a reflexive pronoun, I am the receiver of the action, not that different to the english “me”. For example: Give me your pen - Dame tu bolígrafo / You frighten me - Me das miedo. Mi = my, is a possessive adjective. Este es mi amigo. This is my friend. No fue mi intención hacerte daño. I didn’t mean to hurt you. (Remember to add an ‘s’ when you are referring to more than one thing or something plural – Estos son mis amigos. These are my friends.) Mí = me (with a tilde/escrito con tilde) is a pronoun and is used after a preposition Por mí mismo. By myself. Me lo dió a mí. (To me) he gave it to me. ¿Es para mí? is it for me? Estaremos encantados de saber de ti. We will be happy to hear from you.

Think of "mi, ti, su" as "mine, yours, his/hers". So if you want to say, "my friend" you would say "mi amigo" or "my spanish teacher" would be "mi profesor de español". "me" is what you use when you're talking about someone else doing something to or for you. For example, "He took me to the airport" you would say "Me llevó al aeropuerto". "llevó" is "he brought" and you place "me" before that to show that you were the one he brought to the airport. Another example could be, "you told me yesterday" which would be "me dijiste ayer". Some verbs in spanish are called reflexive, and they can be a bit complicated. I found in the beginning it was easier to just memorize how you say instead of trying to understand why. Some examples are like, "me gusta", "me interesa", "me voy", "me despierto", etc. But if you search "reflexive verbs in spanish" you'll find a ton of info on these verbs and how they work. Hope this helps! ¡Buena suerte en tus estudios!