Four concepts that are related to the English pronoun system?

1. Personal pronouns: These are pronouns that refer to specific people or things, such as "I," "you," "he," "she," "it," "we," and "they."

2. Possessive pronouns: These pronouns show ownership or possession, such as "mine," "yours," "his," "hers," "its," "ours," and "theirs."

3. Reflexive pronouns: These pronouns are used when the subject and object of a sentence are the same, such as "myself," "yourself," "himself," "herself," "itself," "ourselves," and "themselves."

4. Demonstrative pronouns: These pronouns point to specific people or things, such as "this," "that," "these," and "those."

1. Person
2. Number
3. Case
4. Gender