Commas with Introductory Adverbial Elements (I): What Is An Introductory Adverbial Element?
by Tina Blue
SUMMARY: An introductory adverbial element, is any adverbial word, phrase, or clause that appears at the beginning of a sentence, thus changing the normal subject-verb-object pattern of the English sentence. In this article, I explain how to recognize adverbs, and I give examples of the three types of introductory adverbial elements.
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Most of you probably remember from your English classes something about putting a comma after an introductory phrase or clause. I phrase this point vaguely because I believe that for most people, the memory is at least that vague. The purpose of this article is to clarify what those introductory elements are. This article is the first in a series on how to use commas with introductory adverbial elements. The next three articles in this series explain when such an element should be followed by a comma, when it should not, and when the choice depends upon the author's purpose.WHAT IS AN INTRODUCTORY ADVERBIAL ELEMENT?
As you no doubt already know, the natural order for an English sentence is subject-verb, or subject-verb-object, or subject-verb-subject complement. Sometimes we vary this bread-and-butter structure by starting the sentence with something other than the subject (and whatever modifiers belong to the subject). Such an introductory element can be a word, a phrase, or a clause, and in many cases it will function adverbially.WHAT IS AN ADVERB?
There are two types of modifiers in English--adjectives and adverbs. An adjective adds information to (modifies) a noun or a noun substitute (something acting as a noun--a pronoun or a gerund, for example). An adverb modifies a verb or another modifier (an adjective or an adverb).One way to distinguish between adverbs and adjectives is by determining whether the modifier answers an "adjective question" or an "adverb question."Adjective Questions
Which one? How many?What kind of?Adverb Questions
When?Where?Why?How?How much? ( = To what degree?)(The types of adverbs that modify other modifiers are called degree adverbs, and they answer the "How much?" or "To what degree?" question.)
Single words can act as modifiers (i.e., adjectives and adverbs), but so can phrases and clauses. If a phrase or clause modifies a noun or noun substitute by answering one of the adjective questions, then it is an adjectival phrase or an adjectival clause. If it modifies a verb or another modifier by answering one of the adverb questions, then it is an adverbial phrase or an adverbial clause.When an adverb or an adverbial phrase or clause begins a sentence, that structure is a change from the normal subject-verb-object pattern of the English sentence. We refer to adverbial words, phrases, and clauses that appear at the beginning of the sentence as introductory adverbial elements.Here are examples of each type of introductory adverbial element:WORD
Quickly, hide in the closet!Sometimes when the introductory adverbial element is a single word, it will modify not a specific word in the following clause, but rather the entire clause. In this case, the introductory adverb is called a sentence adverb.
WORD: SENTENCE ADVERB
Ironically, the same people who persuaded him to run for office campaigned against him when he sought a second term.PHRASE
In the early spring small flowers begin to bloom, even though sometimes the ground still seems to be frozen.CLAUSE
When the children heard footsteps in the hallway, they jumped back into their beds and pretended to be asleep.--1. In the first example, the word [q]uickly modifies the verb hide, by answering the adverbial question "How?" (Hide how? Hide quickly.)
--2. In the second example, the prepositional phrase [i]n the early spring modifies the verb bloom, by answering the adverbial question "When?" (Bloom when? Bloom in the early spring.)
--3. In the third example, the clause [w]hen the children heard footsteps in the hallway modifies the compound predicate consisting of the verbs "jumped" and "pretended," by answering the adverbial question "When?" (When did the children jump back into bed and pretend to be asleep? They did so when they heard footsteps in the hallway.)
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NOTE:
In "Commas with Introductory Adverbial Elements: II. a. WORDS--When Do You Need the Comma, and When Can It Be Omitted?" , Commas with Introductory Adverbial Elements: II.b. PHRASES--When Do You Need the Comma, and When Can It Be Omitted?" , and "Commas with Introductory Averbial Elements: II. c. ADVERB CLAUSES," I explain how one decides whether to set an introductory adverbial element off with a comma. 
