• Adverbs are the headwords of adverb phrases. It is these phrases, not the words themselves, that function syntactically as adverbial clause elements (or within clause elements as modifiers of verbs and other adverbs).
• The great majority of adverb phrases have a single adverb as their unitary constituent. The only exceptions are phrases such as “very gently” in which the headword, “gently” is modified by another adverb, “very.” Because they normally contain only a unitary constituent, it is convenient and tempting to refer to these adverb phrases simply as “adverbs.” That practice has a serious disadvantage though — from a pedagogic point of view at least — because it obscures the important fact that, strictly speaking, only words (not phrases) can function as immediate constituents of clauses.
• Looked at morphologically — in terms of how they are constructed — adverbs can be divided into three classes:
• simple adverbs: for example, just, only, well, back, near, down, under. (Many simple adverbs refer to position or direction.)
• compound adverbs: which are constructed from two words, for example, somewhere, everywhere, nowhere, therefore, whereupon, hereby
• derivational adverbs: made by adding a suffix to an adjective (or a participial adjective)
- most are made by adding “ly:” strangely, foolishly, interestingly, depressingly
- but other suffixes are used as well; clockwise, westward, sideways, cowboy-style
• closed-class adverbs: The first and second of the three types of adverb listed above — simple and compound adverbs — are closed-class items (also called “function words” or “grammar words”). These are very basic words, absolutely essential even for the most rudimentary linguistic communication. Their meanings are interconnected and they tend to be bound up with particular grammatical structures. All this makes them particularly important for ESL pedagogy. Many closed-system adverbs refer to time. They can be divided into three groups:
1. closed-class adverbs that take their reference in relation to some past time: then, before, since
2. closed-class adverbs that take their reference in relation to the present moment: now, today, tomorrow, yesterday
3. closed-class frequency adverbs: often, always, seldom, never