Converting Latin to English
(Grimm's Law or First Germanic Sound Shift)

f -> b -> p -> f
th -> d -> t -> th
h (gh)-> g -> k -> h (gh)

Try your hand to find the cognates:
frater        mater
pater        nepos
tres           octo
cornu        genu
cordia       gnoscere
frango        ego
tenuis        tonare
fundus        fer--
noctis        ager
pedis        granum
canis        tumere
duo            centum