Commonly Confused Suffixes: -ance and -ancy vs. -ence and -ency

The suffixes “-ant” and “-ent” each have two related noun forms: “-ance/-ancy” and “-ence/-ency.” These are all used to describe a state, quality, condition, or action typically associated with an adjective or noun of agency described by “-ant” or “-ent.”

However, there is not always a direct correlation between the “-nt,” “-nce,” and “-ncy” endings: not every word ending in “-ant” or “-ent” can become a noun ending in both “-ance/-ancy” or “-ence/-ency.” Many roots and base words can indeed take all three endings (e.g., expectant, expectance, expectancy; dependent, dependence, dependency), but many others will only take one of the two possible noun endings (e.g., pregnant becomes pregnancy, but not pregnance; different becomes difference, but not differency). Additionally, there are smaller subsets of words that will only be formed with “-ant,” “-ance,” “-ent,” or “-ence,” without having either of the other two endings.

Note that the rules and conventions for when a word will take “-ance” vs. “-ence” or “-ancy” vs. “-ency” overlap almost entirely with choosing “-ant” vs “-ent,” so this section will focus more on determining when particular “-ant” or “-ent” words have corresponding “-nce” or “-ncy” forms. There are no spelling patterns in such words to help us determine when or if “-ance/-ancy” or “-ence/-ency” can be used, so this section will only look at specific sets of example words. If you want to see more detailed rules for determining which ending is correct, go to the section Commonly Confused Suffixes: “-ant” vs. “-ent”.

The suffixes “-ance” and “-ancy” are simply variants of one another; as such, nouns with these two endings are almost always synonymous, with the only real difference being which one is more common. In the following table of examples, we’ve marked the most common form in bold—if it is overwhelmingly more common, it will be bold and underlined. (Note that we’ll only make this distinction between “-ance” and “-ancy”—we won’t be looking at how common “-ant” is compared to the others.)

As we noted already, though, not every adjective or noun of agency ending in “-ant” will take both “-ance” or “-ancy” to become nouns of state or condition. In fact, more words ending in “-ant” will take only one of the forms, rather than both.

While most “-ant” words will have associated forms ending in “-ance,” “-ancy,” or both, there is also a large number of terms that don’t take either noun ending. There is nothing in the spelling of these words that makes it clear that they will not take either of the two endings, so we just have to memorize them:

While less common, there are also some nouns ending in “-ance” that don’t have associated “-ant” forms. When this is the case, they do not have variant “-ancy” spellings either; they can only be formed from base words or roots using “-ance.”

The suffix “-ent” has the same function as “-ant,” and it has the same behavior when forming nouns ending with “-ence” or “-ency”: many “-ent” words will take both endings, many others will only take one or the other, while still others won’t take either.

As with “-ance/-ancy,” nouns that end in “-ence” or “-ency” are almost always synonymous (though there are a few instances in which the “-ency” form has a slightly different meaning than “-ence”). Like in the previous table, the more common of the two is in bold, and if one is much more common than the other, it will be bold and underlined).

While “-ant” words that can only take “-ance” or “-ancy” split this difference almost equally, “-ent” words are far more likely to only take the “-ence” ending.

(*Note that absorbance also exists, but only in relation to physics—specifically denoting the measure of a substance’s ability to absorb radiation. Absorbent and absorbency are the preferred spelling for all other meanings.)

As with “-ant,” many adjectives and nouns of agency ending in “-ent” cannot be made into nouns ending in either “-ence” or “-ency.”

Finally, there are also words that will only take the “-ence” ending. There are not that many of these words, but quite a few of them are very common in modern English.

Uniquely, the verb tend becomes tendency, not tendent or tendence. This is the only instance in which a word will take the “-ncy” ending, but not “-nt” or “-nce.”