Interpreting is a very complex undertaking that requires more than just knowing “some sign language”. The process of interpreting a message from one language to another requires a high level of proficiency in both languages. A coworker, or someone who is responsible for other duties in your workplace, should not be put in the position of interpreting for a Deaf colleague or customer, as it takes away from their ability to perform their own assigned duties. Furthermore, you will have no guarantee of quality, accuracy, or confidentiality of information when using a person who works in your office. In many cases, more damage has been done by a “signer” who is just trying to help out, which then requires more extensive interpreting time to repair the misunderstandings caused by not calling a professional interpreter in the first place.