Suffix · forms adverbs
Turns an adjective into an adverb that describes how something is done: slow becomes slowly.
Written by Bryan López, English teacher · Updated
The suffix -ly takes an adjective and turns it into an adverb: a word that describes HOW an action is done. From "slow" you get "slowly"; from "quick" you get "quickly"; from "careful" you get "carefully". Adverbs in -ly answer the question "how?". He drives slowly. She speaks clearly. If you know the adjective, you already know the adverb: just add -ly.
Almost every English adverb ending in -ly maps directly to a Spanish adverb ending in -mente. slowly = lentamente quickly = rápidamente clearly = claramente perfectly = perfectamente This means if you already know the English adjective, you get the adverb for free. No extra memorisation needed: adjective + ly = adverb.
Two traps to avoid. First: some -ly words are adjectives, not adverbs: friendly, lovely, lonely, lively. These describe nouns, not verbs. Second: "fast", "hard", and "late" are already adverbs without -ly. "fastly" does not exist. He runs fast (not fastly). She works hard (not hardly, which means "barely").
The main rule is simple: adjective + ly. There are only two common spelling changes.
When the adjective ends in -le, drop the -e and add -y (simple → simply). When it ends in -y, that -y becomes -i before -ly (happy → happily). In all other cases just add -ly as is.
-ly/li/ · light, unstressed 'lee'
Tap the button to hear how the ending sounds. Each word in the table has its own audio.
"fast" is already an adverb on its own. "fastly" does not exist. Same with "hard" and "late".
"friendly" is an adjective (with -ly built in), not an adverb. You cannot use it to modify a verb directly.
When the adjective ends in -y, that -y becomes -i before -ly: happy → happily.
A trick to remember it
Think of -ly as the English version of -mente: slow → slowly, just like lento → lentamente. Know the adjective and you get the adverb free. Remember the two exceptions that travel without -ly: fast, hard.
Exercise 1 · Form the word
Exercise 2 · Pick the right one
What is the correct adverb form of "happy"?
Exercise 3 · Pick the right one
Which sentence is correct?
The suffix -ly turns an adjective into an adverb that describes how something is done: slow becomes slowly. In Spanish it usually maps to -mente.
The ending -ly is pronounced /li/ · light, unstressed 'lee'. For example, "slowly".
"slow" becomes "slowly". It is a typical example of the -ly suffix.
-tion, -ness, -ful, -ly, -able... every ending you need to understand thousands of words at once.