“The most commonly used verb in the English language (and indeed many other languages) has a strange history. The fact that it has so many more forms than other verbs, which are quite unlike each other (be, being, been, is, was, were, am, are) gives us a clue as to its Frankensteinian origins.” (And plenty of languages don’t even use it.) “It’s what some linguists have called ‘a badly mixed up verb.'” – JSTOR Daily