Pronouns drive me crazy
I'm trying to get a handle on when to use tú, tu, te, ti.
I think the following
Tú = you informal
Tu = your
Ti = you
Te = you or yourself
How do I know when to use these?
You're off to a good start. I checked your profile and saw you are completing the lessons. Your next lesson in Lesson 2 is about pronouns. Do that lesson and you will understand more. Also, check out the reference material about pronouns here. That will also help. Other than that, just associate the Spanish pronoun with the English pronoun and remember them that way. I hope this helps.
By the way, they drove me crazy at first too. You are not alone.
I think you need to stand your pronouns upside down or on their side or something. The confusion is not what they mean or translate to but where you use them.
When you want to identify who did it then your first "tú" is the subject of the verb and goes before it. "Tú dices"
When you need a pronoun to identify who is the object of the action, use "te" after the verb. "voy a donarte una respuesta" or, still the object, with the sentance inverted use "te" in front of the verb. "Te voy a contestar". This is really very unusual in English, doesn't "you I'm going to answer" sound wierdo? but it's common in many other languages.
When you need to identify who is at the receiving end of a preposition, use "ti". "Espero que este assunto se aclarara a ti pronto."
When you want to identify who owns what, use the possesive pronoun, "tu". "Tu profesor quedara orgulloso de tu progreso". This "tu" turns into "tus" when you need to use it with a plural or multiple objects.
Ouch! That's a lot of words but that's how it is. Good Luck.