Pronouns are a rather easy aspect in any language, but they have to be learnt by heart, and if you don't study, they can be really tricky.
. THey are the subject of the sentence, so, they appear at the beginning. They have verb concord. I,YOU, HE, SHE, IT, WE YOU THEY
POSSESSIVE ADJECTIVES THey are not pronouns, and they express possession; they accompany nouns, so, their position is before the noun they go with.
-My, your, his/her/its, our, your, their
e.g. My dog is small. //// Your friends study hard//////
OBJECT PRONOUNSObject pronouns can be confused with personal pronouns because their meaning is the same, the only difference it the position. They always appear after the verb or after prepositions, because their syntactic function is COMPLEMENTO CIRCUNSTANCIAL, COMPLEMENTO DIRECTO, COMPLEMENTO INDIRECTO
-ME, YOU, HIM/HER/IT, US, YOU, THEM
E.G. Peter gave Mary a present: He gave her a present
I go out with my friends: I go out with them
-These can be tricky, because you mix them with the possessive adjectives. pOSSESSIVE PRONOUNS REALLY REPLACE NOUNS AND EXPRESS POSSESSION. They are not followed by anything
MINE, YOURS, HIS/HERS/ITS, OURS, YOURS, THEIRS
e,g, This car belongs to me: This car is mine
Here, you have some links with activities and more explanations:
Finally, a mix of activities of different levels with all kinds of pronouns: