When you engage a lawyer, a doctor or a tradesman you have an expectation that the person doing the job is trained and qualified and has specialist expertise in their field.  An interpreter or translator is no different. 

Interpreting and translation is a complex skill set and accredited interpreters and translators have completed rigourous training and testing to ensure their skills are of a nationally recognised standard.  Accredited interpreters and translators are also required to abide by a code of ethics and are accountable for their actions and their interpretations.

Bilingualism does not mean that a person is able to interpret or translate information. It can often be tempting to use someone's mother or child, or sibling to interpret or translate information but this should be avoided at all costs.  A family member or friend may not have the necessary fluency in both languages, or the ability to interpret accurately. They are not bound by ethical constraints such as impartiality and confidentiality.

Your client has a right to ethical, professional, accurate and confidential interpretation.