Words used the most evolve the slowest. Researchers have traced how past tense forms of English verbs have died out since the time of Beowulf. Only one persists as a rule: adding “-ed” to denote the past tense (so-called regular verbs). The investigators catalogued all the irregular verbs they came across, such as “sing”/“sang,” as well as those that have since been regularized (such as “slink,” which is now “slinked” but 1,200 years ago was “slunk”). Only 98 of the 177 irregular verbs they found have not been regularized, and given two verbs, if one was used 1/100 as frequently, it evolved 10 times faster. Next to fall, they predict: “wed,” the past tense of which will regularize to “wedded.” The October 11 Nature published this study, as well as a similar one comparing soundalike words across Indo-European languages.