There are two good reasons for incorporating historical linguistic insight into second language instruction: (1) to answer students' questions about why certain puzzling facts and irregularities occur in the language they are studying; and (2) as in other disciplines, a historical perspective can shed light on current practice. From a historical perspective, it can be seen that many suspected irregularities in the language being studied are not really irregular at all, a fact that is interesting and satisfying to students. While long explanation and coverage of all grammatical points from a historical viewpoint is not recommended, common questions raised by students may be addressed with brief historical accounts. Some of these answers may also have practical value in facilitating the learning of correct grammatical forms. The use of historical linguistic information can replace the typical inaccurate, uninteresting, and unhelpful responses so often given to students who question the patterns in a target language. (MSE)