(idea) by Muke Mon Oct 09 2000 at 2:45:29

The first stage of Grimm's Law is the Germanic consonant shift, whereby these Proto-Indo-European phonemes changed their values: 

    Indo-European       Germanic
    =============       ========
     p   b   bh         f  p  b
     t   d   dh    -->  th t  d
     k   g   gh         h  k  g
     kw  gw  ghw        hw kw gw

So, for example, PIE *pod- becomes *fot- in Germanic (ending up eventually as 'foot' in English). To compare to another language, *bher- in Greek produces 'pherein' ("to carry") and *beran in Germanic (becoming 'to bear' in English).

The second stage in Grimm's Law is the High German consonant shift, which applies (aptly) to High German, and also apparently appeared in the East Germanic language Lombardic. It changed p, t, and k to (p)f, (t)s, and (k)h. (I'd give the full changes but I can't find them right now.)

FYI, the Jakob/Jacob Grimm in Grimm's Law is one of the Brothers Grimm, the very same Grimm as in Grimm's Fairy Tales.

I like it!