From Middle English -ly, -li, -lik, -lich, from Old English -līc, -līċ, from Proto-Germanic *-līkaz (“having the body or form of”), from *līką (“body”) (whence lich). Cognate with Dutch -lijk, German -lich and Swedish -lig, and with English -like (from Proto-Germanic *līka-).
- Used to form adjectives from nouns, the adjectives having the sense of "like or characteristic of what is denoted by the noun".
- Used to form adjectives from nouns specifying time intervals, the adjectives having the sense of "occurring at such intervals".
In casual usage, -ly is sometimes omitted from adverbs (e.g., badly becomes bad). This is proscribed (considered improper grammar) by many: “I want it badly.” being preferred to “I want it bad.”, for example.
Various sound changes and spelling changes occur for -ly:
- If an adjective ends with the letter y, it changes into i before adding the suffix (e.g. ready, readily).
- If an adjective ends with ble, these euphonically blend to bly, due to difficulty of pronouncing *blely. Examples include -ably and -ibly, but also feebly, nimbly, and nobly, among others.
Old English, see above
- -ly (suffix used to form adverbs)