Forms and types

An adverb can be a word or a phrase or a clause. Dealing first with words, we can recognize two basic forms:

1. Those which are derived from an adjective by adding -ly, and which maintain the meaning (or a major part of the meaning) of the adjective; for example, quickly, rudely, narrowly, humbly, simply, probably, sensibly.
2. The rest, which further divide into two sub-kinds:

IIa. Those which end in -ly, but have a quite different meaning from the form obtained by deleting the -ly. They include hardly, fairly, really, terribly.

IIb. Those which do not end in -ly. Most of these are not morphologically analyzable; for example, quite, just, even, also, plus time adverbs such as still, now, soon, then, and spatial adverbs such as here and out. Others have an historical analysis but are perceived as unanalyzable forms in the modern language. They include almost, somewhat, and time adverbs such as always, today, tomorrow and yesterday.

In fact, the division between I and IIa is not clear-cut. Some adverbs ending in -ly have a degree of semantic similarity to the corresponding adjective, but not so much as prototypical members of I; for example, truly, scarcely, surely, simply.

Speakers of some dialects of English may in certain circumstances omit the -ly so that adjective and adverb have the same form; for example, I want it real bad (in place of I want it really badly). Note that this applies not only for adverbs of type I (badly) but also for some of type IIa (really).

Just a few adjectives function in Standard English as adverbs without the addition of -ly; for example, hard as in He’s a hard (adjective) worker and he also plays hard (adverb).

Adverbs can be derived from adjectives which are themselves derived from nouns; for example, noun geography giving adjective geographical giving adverb geographically. And a few adverbs are directly derived from nouns by adding -ly; for example, partly and purposely (there is also adverb purposefully, derived from adjective purposeful, which is in turn derived from noun purpose).

A number of the most frequently used adverbs are traditionally written as two words but in fact function as a single (phonological and grammatical) word in present-day English. These include:

Most of the discussion here concerns single-word adverbs. There are also adverbial phrases (often called adjuncts). Many—but by no means all—manner adverbs which are derived from adjectives by adding -ly can be replaced by a phrase in a [adjective] manner/way; for example, in a rude manner has very similar meaning to rudely (but exhibits more formal overtones). Many phrases function as time adverbs (with there being no single-word equivalent); for example, in the morning, at night—which include a preposition—and last night, every night—which don’t.

Spatial adverbs generally consist of a preposition with local meaning followed by an NP—in the house, up the tree, around the garden. The NP can often be omitted, leaving just the preposition, as in I’ve put the cake in (sc. the oven) and The lodger went up (sc. the stairs). Grammarians have long been disputing whether up in The lodger went up is a preposition implicitly followed by an NP which has in this instance been omitted, or an adverb which is homonymous with the preposition. Arguments can be put forward in favor of both positions; which is followed remains a matter of personal choice.

Adverbial clauses typically have time or spatial reference; for example, We’ll stop work when the sun sets, and I’ll plant the fuchsias where you planted the rhubarb. Some grammars describe subordinate clauses introduced by links such as although or if as adverbial clauses.