Lack of fluency in the language of instruction can form a barrier to medical education. There has been an effort within Australian universities to teach English to students from non-English speaking backgrounds (NESB), but little systematic attention has been given to the teaching of informal or colloquial English. This paper provides evidence that colloquial language is a pervasive and important aspect of doctor-patient communication. It describes a teaching project for NESB medical students which aimed to introduce them to colloquial English, and to provide them with a contextual approach to learning this form of language. Forty-four first year medical students enrolled at the University of Adelaide were required to gather examples of colloquial language by interviewing a native English speaker. Ninety-four examples of colloquial sayings were recorded. These were compiled in the form of a handbook which served as a student resource. Student evaluation of this exercise was positive. The benefits of an interactive method of teaching local and setting-specific language are discussed, and the implications of this approach for clinical teaching and for medical practice are explored.