> It's possible that common verbs are irregular in a lot of languages. Maybe it's because they were "invented" before someone decided to set down grammatical rules, and then the only way to create less common verbs was to have conjugation rules for them.

This is quite possible, though to my mind, it seems like those common words would be the ones most used, and those words are the ones that tend to mutate over time.

-Cynth"ser, Spanish, "to be," AND ir, "to go," preterite tense: fui, fuiste, fue, fuimos, fuisteis, fueron -- go figure THAT one out"ia