If you’re like me, you’ve probably used these two words interchangeably. They have the same root, after all, are both adverbs, and as far as you know, mean precisely the same thing.
Anymore, to a great degree, that’s true, since modern usage has more or less collapsed their respective connotations into a single synonymous pair of words. But to purists, there’s still a difference, and it used to be more widely-understood.
Here’s the difference in a nutshell:
- Continual refers to something that is recurring; e.g. the sun continually rises each morning.
- Continuous refers to something that is unceasing; e.g. my heart is continuously beating1.
Both words ultimately come from the Latin continuus—”uninterrupted”—but Old French absorbed it twice. Continuer (continuous) is from the 13th century; continuel (continual) is from the 14th century.
There are a couple of pairs of words like this in modern English (mostly notable “special” and “especial,” though you so rarely see anything but the adverbial form of the latter nowadays).
- Knock on wood.[↩]