Yo estoy cansado.
English: I am tired.
Subject pronouns replace names at the start of a sentence and connect to verbs like ser, estar, and tener. In Spanish, they are often omitted because the verb form shows the subject.
Use subject pronouns for clarity or emphasis, or when the subject is not clear from context.
Yo estoy cansado.
English: I am tired.
Ellos son amigos.
English: They are friends.
Él no sabe.
English: He does not know.
Hace frío.
English: It is cold.