Here's why:
* Subject pronouns are used when the pronoun is the subject of the verb in a sentence. For example:
* We went to the store. (We is the subject of the verb "went")
* Object pronouns are used when the pronoun is the object of the verb or a preposition. For example:
* The store gave us a discount. (Us is the object of the verb "gave")
Let me know if you'd like to explore other pronoun types!