Suffix · forms verbs
Turns an adjective into a verb meaning "to make X" or "to become X": dark becomes darken.
Written by Bryan López, English teacher · Updated
The suffix -en takes an adjective (or occasionally a noun) and creates a verb meaning "to make something become X" or "to become X". From "dark" you get "darken"; from "wide" you get "widen"; from "short" you get "shorten". What makes these verbs special is that they are both causative ("to make") and inchoative ("to become"): "The sky darkens" and "the clouds darken the sky" are both valid uses of the same verb.
English -en verbs do double duty in a way that often surprises learners. "Her face brightened." (intransitive: her face became brighter) "The news brightened her mood." (transitive: the news made her mood brighter) The same verb works in both directions. This makes -en verbs compact and expressive — one word covers what Spanish might express with two different constructions.
Not all adjectives take -en. The practical rule: -en works well with short adjectives of one or two syllables ending in a consonant. Work: dark → darken, wide → widen, short → shorten, bright → brighten, deep → deepen. Do not work: beautiful, intelligent, comfortable (too long — use "make more X" or "become X" instead). When the adjective has more than two syllables, use "make it more X" rather than forcing -en onto it.
Short adjective (1-2 syllables) + en. A few spelling adjustments apply.
When the adjective ends in silent -e (wide, white, loose), just add -n: widen, whiten, loosen. When it ends in consonant-vowel-consonant with final stress (flat, mad, sad), double the last consonant: flatten, madden, sadden.
-en/ən/ · soft, unstressed 'un'
Tap the button to hear how the ending sounds. Each word in the table has its own audio.
-en only works well with short 1-2 syllable adjectives. For longer ones, use "make/become more X".
The -en suffix is unstressed. Stress stays on the original adjective syllable: DARKen, WIDEn, SHORTen.
When the adjective ends in silent -e, just add -n: white → whiten, wide → widen.
A trick to remember it
Think of -en as "to make/become [adjective]": darken = to make dark or become dark, widen = to make wide or become wide. Short adjectives only. For longer ones, use "make more" or "become".
Exercise 1 · Form the word
Exercise 2 · Pick the right one
What is the -en verb form of "wide"?
Exercise 3 · Pick the right one
"The sky darkened." This means...
The suffix -en turns an adjective into a verb meaning "to make X" or "to become X": dark becomes darken. In Spanish it usually maps to -ecer / -ar.
The ending -en is pronounced /ən/ · soft, unstressed 'un'. For example, "darken".
"dark" becomes "darken". It is a typical example of the -en suffix.
-tion, -ness, -ful, -ly, -able... every ending you need to understand thousands of words at once.