Topic summary
Sound laws
Extracted from the Wikipedia article Sound change.
The Neogrammarian linguists of the 19th century introduced the term sound law to refer to formulations of regular change, perhaps in imitation of the laws of physics, and the term "law" is still used in referring to specific sound changes that are named after their authors like Grimm's law and Grassmann's law. Real-world sound laws often admit exceptions, but the expectation of their regularity or absence of exceptions is of great heuristic value by allowing historical linguists to define the notion of regular correspondence by the comparative method.