Answer:
"usted" is the more formal way to speak to an adult or someone older than you in Spanish while "tu" can be used when you're speaking to someone like a friend and that you have a chill and laid back connection with.
Explanation:
Estoy triste porque no me acorde
Nadar
Ingeniero quimico
diseñadora del inteior de las casas
Marta es inteligente y generosa
