To become en relación con un sustantivo describe un cambio, que una cosa / persona se convierte en lo que el sustantivo describe. Para traducir este tipo de frase al español muy a menudo hay que cambiar completamente la estructura de la frase.

to become ...
an American citizen convertirse en ciudadano americano Years later, he became an American citizen.
a burden convertirse en un fardo He didn't want to become a burden to his family.
a Catholic hacerse católico In her late 50's, she became a Catholic.
a doctor hacerse médico He always wanted to become a doctor.
a father hacerse padre Unexpectedly, he became a father.
a laughing-stock ponerse en ridículo I tried to avoid becoming a laughing-stock.
a legend convertirse en una legenda Elvis soon became a legend.
a man convertirse en un hombre Finally, he became a man.
a member hacerse miembro You do not want to become a member in the club.
an orphan convertirse en huérfano Unfortunately, I became an orphan very young.
bail avalar In this difficult situation, he became bail for his friend.
friends hacerse amigo They became friends 10 years ago.
reality convertirse en realidad His dreams became reality.
suspect convertirse en sospechoso He suddenly became their main suspect.
the fashion ponerse de moda Miniskirts became the fashion in the seventies.