The Grammarphobia Blog

Whence “-ency” and “-ence”?

Q: I’ve wondered about this one for a while and didn’t know (until I discovered your blog) whom to ask about it. Why is everyone saying “insurgency” and not “insurgence”? We don’t say “resurgency,” do we? We say “resurgence.”

A: We’ll start by saying that both “insurgence” and “insurgency” are legitimate nouns.

The first means an act of rising up against authority, and the second generally means a state or condition of being insurgent. There’s a very subtle difference here, and in fact “insurgency” can be used both ways.

By the way, “resurgence” and “resurgency” are legitimate words too, and we’ll have more to say about them later.

Your question illustrates an interesting point about English. It’s a very expansive language, and it has many suffixes for forming new nouns from adjectives, verbs, and other nouns.

Some of the most familiar noun-forming suffixes are “-ence,”
“-ency,” “-ance,” “-ancy,” “-acy,” “-cy,” “-ment,”
“-ation,”
“-age,” “-ness,” “-ship,” and “-ism.”

The ones we’re concerned with here are the first two, “-ence” and “-ency,” which can be traced to a suffix the Romans used to form nouns: the Latin -entia.

To speakers of English, it would seem, nouns are like peanuts. We can’t have just one.

So over the centuries we’ve frequently formed twin nouns by appending both “-ence” and “-ency” to the same base.

Often, according to the Oxford English Dictionary, one of the twins quietly drops out of the picture.

But sometimes both survive, as with “persistence” and “persistency,” “coherence” and “coherency,” and others. Both forms are legitimate, and though the differences are often extremely subtle, they aren’t haphazard.

The suffixes “-ence” and “-ency” have played different roles in the development of English nouns.

As the OED explains, the Latin suffix -entia yielded two types of nouns, those representing “action or process” and those representing “qualities or states.”

In English, the first type (ending in “-ence”) is more closely associated in meaning with its corresponding verb, the second type (“-ency”) with its corresponding adjective.

When the same word exists in both the “-ence” and “-ency” forms, there’s often only a fine line of difference.

We can see how this works in the case of “insurgence” and “insurgency.”

The first to appear, “insurgency,” was coined around 1800 as a noun meaning the state of being insurgent. Only later did the concrete sense (an insurgent movement or revolt) develop.

The second to appear, “insurgence,” was coined in the 1860s to mean the act of rising against authority. So though the words overlap, both are legitimately used today to mean an insurrection.

Merriam-Webster’s Collegiate Dictionary (11th ed.) defines “insurgence” as “an act or the action of being insurgent.”

M-W defines “insurgency” as “the quality or state of being insurgent; specif: a condition of revolt,” and includes “insurgence” as a second definition.

Similarly, “resurgence” and “resurgency” are legitimate nouns, both now meaning the act of rising again.

“Resurgency” was first recorded in 1798 and “resurgence” in 1810, according to OED citations.

While you’ll find “resurgency” in the OED, however, it’s not often used and it isn’t included in standard dictionaries. So it’s probably dying out.

As we were writing this, we thought of two extremely different twin nouns, “emergence” and “emergency,” both of which appeared in the 17th century.

The older of the two, “emergency” originally meant a “state of things unexpectedly arising” and demanding immediate attention, the OED says.

“Emergence,” on the other hand, meant an action—the act or process of emerging, as from a hidden or submerged place.

But for much of their history, “emergence” and “emergency” were used interchangeably in both senses.

For example, in his Memoirs, written sometime before 1676, the historian Henry Guthry writes, “The Castle of Dunglass was blown up with Powder,” an event he later refers to as “this tragical Emergence.”

With two such different meanings, however, there was room for two distinct nouns. So over time the two became increasingly different. Today, as a result, an “emergence” is vastly different from an “emergency.”

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