There are a few different ways to express “to become” in Spanish. I don’t claim to be an expert, just so you know. But the following are my notes from today’s study:

Volverse = to turn into (something that is not planned)

• Se volvió un estúpido. He turned into an idiot.
• Se volvió una buena persona. She became a good person.

Hacerse = used for something you do on purpose, or to work to become

• Se hizo enfermera. She became a nurse. (She worked to become a nurse.)
• Me hice cantante. I became a singer. (I worked to become a singer.)

Convertirse en = to evolve into, to transform into (The en needs to be included.)

• Se convirtió en una mariposa. It became a butterfly.
• El niño se hizo un hombre. The boy became a man.

Ponerse =  followed by an adjective and indicates an involuntary physical or emotional change

• Te pusiste enfermo en Ecuador el año pasado. You got sick in Ecuador last year.
• El cantante se pone rojo cuando canta. The singer turns red when he sings.