Subject pronouns are used to replace nouns that are the subject of a sentence.
Here are some examples:
* I went to the store. (I is the subject pronoun replacing the noun "I")
* She is a talented musician. (She is the subject pronoun replacing the noun "She")
* They love to play soccer. (They is the subject pronoun replacing the noun "They")
Remember: Subject pronouns perform the action of the verb in the sentence.