General:
* Ser guardião/guardiã: This is the most direct translation, meaning "to be a guardian."
* Ter a guarda: This literally means "to have custody," and is often used when referring to legal guardianship of a child.
* Exercer a guarda: This means "to exercise custody," and emphasizes the active role of the guardian.
Specific types of guardianship:
* Ser tutor/tutora: This refers to a legal guardian appointed by a court, especially for minors or individuals who are unable to take care of themselves.
* Ser curador/curadora: This refers to a guardian appointed by a court to manage the affairs of someone who is incapacitated.
* Ser responsável: This means "to be responsible," and can be used to refer to someone who takes care of another person, though it doesn't necessarily imply legal guardianship.
Examples:
* Ele é o guardião do seu sobrinho: He is the guardian of his nephew.
* A mãe tem a guarda dos filhos: The mother has custody of the children.
* Ela exerce a guarda do seu irmão: She exercises custody of her brother.
* O juiz nomeou um tutor para a criança: The judge appointed a guardian for the child.
The best choice depends on the specific situation.