found 2220 obsolete 1-gram headwords (“diestock”, But the -t irregulars may be doomed in England too: each “alkalescent”) in AHD4. Their mean frequency declined year, a population the size of Cambridge adopts “burned” in throughout the 20th century, and dipped below 10° decades lieu of “burnt.” ago (Fig. 2D, Inset). Though irregulars generally yield to regulars, two verbs Our results suggest that culturomic tools will aid did the opposite: light/lit and wake/woke. Both were irregular lexicographers tn at least two ways: (1) finding low-frequency in Middle English, were mostly regular by 1800, and words that they do not list; and (41) providing accurate subsequently backtracked and are irregular again today. The estimates of current frequency trends to reduce the lag fact that these verbs have been going back and forth for between changes in the lexicon and changes in the dictionary. nearly 500 years highlights the gradual nature of the The Evolution of Grammar under i . . Next, we examined grammatical trends. We studied the uly ieee os al leastone instance ef rapid PISEress by English irregular verbs, a classic model of grammatical oe mreeu EL om. Presently, 1% of the English speaking change (/4-/7). Unlike regular verbs, whose past tense is popuron Syltches Fem “eureakext* to “iserake” every year generated by adding ed jump/jumped), irregulars are someone will have snuck off while you read this sentence. As conjugated idiosyncratically (stick/stuck, come/came, get/got) before, this trend is more prominent in the Dnited States, but (15). recently sneaked across the Atlantic: America is the world’s o All irregular verbs coexist with regular competitors (e.g., sadly ex potics (et Beth neg manta tele alan wens. 5 “strived” and “strove”) that threaten to supplant them (Fig. Out with the Old a 2E). High-frequency trregulars, which are more readily Just as individuals forget the past (/8, 19), so do societies 7 remembered, hold their ground better. For instance, we foun