A reader wonders when the term “modal verb” began to be applied to the following helping verbs: can, could, may, might, shall, should, will, would.
Writes the reader:
When I was young, no teacher or college professor whose subject was English ever mentioned “modal” with respect to verbs. So, what’s with the “modal” stuff? “Modal” seems to me to be nothing more than a current trend. Can you tell whence and when “modal” sprang into being?
Like this reader, I went a very long time before hearing these helping verbs called “modals.” The first time I heard the term was in graduate school—and I’d taught high school English for several years before going there.
The Ngram Viewer shows the existence of “modal verbs” in printed books as early as 1848, but the term’s use begins to soar in the 1960s.
The earliest OED citations for “modal verbs” in the context of grammar are dated 1933, the year that saw the publication of an influential textbook based on structural linguistics: Language, by Leonard Bloomfield (1887-1949).
The importance of structural linguistics declined in the 1950s and 1960s as Chomsky’s theory of “generative grammar” displaced it, but the term “modal verbs” remained popular.
Modal verbs are also called modals, modal auxiliary verbs, and modal auxiliaries. These helping verbs are used to show if the speaker believes something is certain, probable or possible (or not). For example:
I may be able to travel to Tulsa with you.
Must you contradict everything I say?
Will my car be ready by this afternoon?
Modals are also used to talk about ability, to ask permission, to make a request or an offer, and so on. For example:
He could not lift the weight.
May I go with my friends to the mall?
As for being a “current trend,” the term may have been a trend in the 1960s, but after half a century, modal verbs are in the day-to-day grammar lexicon to stay.