Pronouns are essential for writing or speaking. Your recall has to be without hesitation. A light hesitation before answering not good enough. If I say, "when counting, what comes after 45?" you can answer without thinking. Do likewise with all these pronouns. You want immediate and accurate .
Go to the Vocabulary Section:
1) master the set of Pronoun Icons.
2) then master the Subject Pronouns,
3) then master the Object Pronouns,
4) then master the Possessive Pronouns and Possessive Adjectives,
then return to this Grammar section.