How to tell the difference between continuous and continual

Among the most irksome aspects of the English language are those almost-identical pairs of words we think of as interchangeable but which really aren’t. Continual and continuous. Ensure and insure. Compose and comprise.

These double-minted demons seem to have been created by some malevolent dictionary god for no other purpose than to make us mortals embarrass ourselves by using them incorrectly—like pulling strenuously on a door marked “push” or confusing the names of our children. Following is a cheat-sheet of some of the more common tweedledee-tweedledum words, with just enough detail to clarify how they differ:

Imply: to indicate or suggest without explicitly stating
Infer: to derive by reasoning, evidence or other non-explicit cues

Continual: continuing on a frequent or regular basis
Continuous: continuing without a break or interruption

Elicit: verb meaning “to draw forth via questions or actions”
Illicit: adjective meaning “illegal or otherwise forbidden”

Sensual: pertaining to gratification of the senses and physical pleasure
Sensuous: relating to or affecting the senses rather than the intellect

Ensure: to make sure something happens
Insure: to protect something—e.g. one’s life, home, health or Jaguar XF—with an insurance policy

Affect (verb): to impact or influence
Effect (verb): to bring about or cause something to occur

Affect (noun): an emotional response that impacts thoughts or actions
Effect (noun): a change brought about by an action or other event

Compose: to make up
Comprise: to consist of or include

Its: the possessive form of “it”
It’s: contraction of “it is”

Flout: to ignore the rules
Flaunt: to show off

Disinterested: impartial—having no dog in the fight
Uninterested: indifferent—not caring about

Discomfort: to make someone physically, mentally or emotionally uncomfortable
Discomfit: to embarrass or make uneasy

Tenet: a principle or belief
Tenant: a resident of a rental property

Amuse: to make someone smile or laugh or keep them happily occupied
Bemuse: to confound, confuse or bewilder

Finally, a special comment on aver and avow, both of which show up regularly in the New York Times crossword puzzle. Aver means “to assert, allege or state something to be the case.” Avow means “to openly assert a truth, often under an assumed or literal pledge.” In all candor, we’ve never gotten the two words straight and have no confidence we ever well.

We have a sneaking suspicion that the Times puzzlemakers know that.