Interesting question. To complicate things, 1'. Hast du dich in den Finger gestochen? would also be correct. OTOH, "Hast du dir gestochen?" is wrong, "Hast du dich gestochen?" is correct. Let me make some more examples: Hast du dir weh getan? Hast du dir etwas gebrochen? Hast du dir Mühe gegeben? In all these cases, the verb pattern uses the dative case: jemandem weh tun, jemandem etwas brechen, jemandem etwas geben. With "stechen", the verb pattern is "jemanden stechen" but also "jemandem in etwas stechen" (Ich habe ihm in den Finger gestochen). So I would conjecture that the "real" reflective pronoun (the one that is part of the verb pattern) always uses the accusative case, but of course one can always fill in the verb pattern with a pronoun that happens to refer to the same person as the subject (I don't know the official name for that. "Accidental" reflective prounoun?), and in that case the dative case is also possible. I would also say that normally one can not interchange the dative or accusative case. It's possible that the verb pattern(s) allow both (possibly with a different meaning or nuance of meaning), but even then it's not a simple interchange.

Ich habe MICH gestochen. Ich habe MIR den Finger gestochen. You use the dative reflexive when the actual object of the verb belongs to the subject. In this case the finger clearly belongs to you. There are a number of mistakes in your example sentences. Now you can correct them. A few more: Ich wasche mich. Ich wasche mir die Hände. Ich habe mich verletzt. Ich habe mir das Bein verletzt.

Hi, Usage of mir it means "to me" zum biespiel 1) "give the book to me" gibst du mir ein Buch? 2) "bring the book to me" bringst du mir ein Kaffe? The case of "mich" bedeutet "me" auf english is erklaret below 1) "will you take or love me" libst du mich 2)can you hear me kannst du mich horen? Similarly dich or dir (you or to you) 1) love you liebe Dich (not Dir) 2) I will give it to you ich werde es dir geben. Also depending on prepostion (dative prepo) mit --> mir or dir (accustaive prepo )fur --> mich or dich I hope it helps.