What’s the difference between "continual" and "continuous"?

The words "continual" and "continuous" are a bit like twins: they both originate from the word "continue," but they are not interchangeable. "Continual" includes beginnings and endings, while "continuous" implies no interruptions.

Continual

"Continual" refers to things that come and go, such as quarrels or rain. The duration of these things extends over a long period, but with interruptions. For example:

• If continual arguing in the office drives you crazy, you know that there are periods when there is no arguing.
• If there are continual rains, there are always sunny breaks, as the Irish meteorologists like to say.

Or consider this passage about the birth of Lynyrd Skynyrd:

"There were continual battles between authority figures like Skinner and the free spirits who formed the band." (herald-review.com)

Continuous

"Continuous," on the other hand, means uninterrupted. This adjective describes something that occurs without any interruptions. For example:

• If the young Skynyrds had had a continuous argument with authority, they would never have stopped, not even to sing "Free Bird."
• In continuous rain, you never see the sun.

Other examples of "continuous" include:

• "Jongeward and Woodhouse ended up breaking the record for continuous flight. They stayed in the air for 1,124 hours." (Yuma Sun)
• "A telegraphic signal would go more than seven times around the earth in one second if it traveled on one continuous wire." (Elmer Ellsworth Burns)
• "The continuous humming of the fluorescent lights gave him a headache."

Using continual and continuous in different contexts

If we also consider the adverbs "continually" and "continuously," the words retain the same distinction:

• "In this part of the country, it rains continually during April."
• "The child screamed continuously for the entire time his mother was on the phone."

"Continual" is chronic, like a cough that comes and goes or a teenager's sporadic arguments with his father. "Continuous" is like a cycle or a merry-go-round of horrors that never stops. Neither is the evil twin; they both just share a mischievous bond of persistence. While one playfully teases, the other tirelessly endures.