The half-life of irregular verbs scales withOCT 17 2007

The half-life of irregular verbs scales with the square root of usage frequency. "Be" and "have" will be irregular for a long time but "dive", "sting", and "wring" have less time before they're regularized.

The past-tense of regular verbs end in "ed." For example, the past-tense of chide was chode, but has now regularized into chided.

Another recent study has found that the evolution of words decreases with usage. Nature has the abstract of the paper and the NY Times has a short piece as well.

"Bird," for example, takes many disparate forms across other Indo-European languages: oiseau in French, vogel in German and so on. But other words, like the word for the number after one, have hardly evolved at all: two, deux (French) and dos (Spanish) are very similar, derived from the same ancestral sound.