Those Old IE Sound Laws
I've spent the better part of the last two days (or so it seems) either explaining to students how Grassman's Law can possible explain exceptions to Grimm's law when it didn't even occur in Germanic or trying to convince them that there is some reason that they should learn what Grimm's Law, Verner's Law, Grassman's Law, and the Great English Vowel Shift are. It isn't as easy as you might think. Undergraduate students can be stubborn debaters, particularly when testable material is at stake.
What I have told them, more listlessly than would be ideal, is that a knowledge of these sound changes is part of the shared intellectual tradition of historical linguistics and that they're also good examples of particular kinds of sound changes. They didn't seem convinced.
I hope that has less to do with my rhetorical skills that their desire to avoid memorizing Greek and Sanskrit examples.