Conjunctions link words or groups of words to other parts of the sentence and show the relationship between them. The four basic conjunctions are coordinating conjunctions, correlative conjunctions, subordinating con- junctions, and linking adverbs.

Coordinating Conjunctions

Coordinating conjunctions and, but, or, and nor join two or more elements of equal rank. The conjunctions but and nor often are used with the adverbs never or not.

The elements joined by coordinating conjunctions can be single words—nouns, verbs, adjectives, adverbs, pronouns—or phrases or clauses. (Clauses are groups of words with a subject-verb combination such as when she came to work or because they are sailing tomorrow.)

• • The telescope and its lens were repaired. (nouns)
  • We called and called, but no one answered. (verbs)
  • He is a sore but victorious player tonight. (adjectives)
  • You can have it done quickly or thoroughly. (adverbs)
  • She and I seldom agree on anything. (pronouns) 
  • We can go over the river or through the woods. (prepositional phrases)
  • Did you know that he’s never eaten a hot dog, had a real root beer, nor played miniature golf? (verb phrases)
  • She went home last night and found the jury summons waiting for her. (clauses)

Correlative Conjunctions

Correlative conjunctions are coordinating conjunctions used in pairs, and they emphasize the elements being joined. Some of the most frequently used correlative conjunctions are as follows:

both . . . and
either . . . or
neither . . . nor
not only . . . but also

Correlative conjunctions also join elements of equal rank. Make sure that the elements following each part of the construction are truly equal.

• • E-mail either Judith or Andy about the party. (nouns)
  • It is both raining and snowing outside. (verb forms)
  • The trade talks were neither hostile nor overly friendly. (adjectives)
  • He not only installed a new DSL line but also added the latest CD burner. (verb phrases)

Subordinating Conjunctions

Unlike the conjunctions described in the preceding section, subordinating conjunctions join elements of unequal rank in a sentence. These elements are usually a subordinate clause (a group of words with a subject-verb combination that cannot stand alone) and an independent clause. Following is a list of commonly used subordinating conjunctions.

after although as as much as because before	how if in order that inasmuch as provided since	than that though unless until what	when where which while who/whom whoever/whomever

Subordinating conjunctions can be used to introduce a sentence as well as to join elements within it. When a subordinate clause comes at the beginning of a sentence, it is followed by a comma. No comma is used when the subordinate clause comes at the end of the sentence.

• • Before we left the theater, I had to dry my eyes.
  • I had to dry my eyes before we left the theater.
  • Provided the books arrive, we can start class Tuesday.
  • We can start class Tuesday provided the books arrive.

Restrictive and Nonrestrictive Clauses. Some clauses provide additional information about a person, place, or object within a sentence. When the clause is essential to the meaning of that sentence, it is known as a restrictive clause. When it is descriptive but not essential, it is called a nonrestrictive clause.

Restrictive:

The city that was built along the river escaped the fire. (The clause that was built along the river distinguishes this city from all others in the area. The information is essential to the sentence.)

Nonrestrictive:

The city, which was built along the river, escaped the fire. (In this sentence, the clause which was built along the river is simply descriptive information.)

Notice that the subordinating conjunction changes from that in a restrictive clause to which in a nonrestrictive clause. In general, that is used to indicate information essential to the meaning of the sentence. Which indicates information that is not essential.

To decide whether a clause is restrictive or nonrestrictive, eliminate the clause from the sentence and determine if doing so changes the meaning.

• • The accountant who works for John has been missing for three days.
  • The accountant, who works for John, has been missing for three days.

In the first sentence, who works for John identifies which accountant among several is missing. The second sentence implies that the accountant, as opposed to the receptionist or some other individual, has been missing. The information who works for John can be eliminated without changing the meaning of the sentence.

Linking Adverbs

Linking adverbs are used to join two independent clauses, that is, clauses with a subject-verb combination that can stand alone. Linking adverbs indicate the relationship between two ideas expressed in independent clauses. In general, linking adverbs reflect results, contrast, or continuation.

RESULTS	CONTRAST	CONTINUATION
accordingly as a result therefore thus	nevertheless however nonetheless conversely	furthermore further in addition also

Linking adverbs can come at the beginning of the second clause they are joining. In such cases, they are usually preceded by a semicolon and followed by a comma. They also can stand within the second clause or sentence and often are set off by commas.

• • We arrived late at night; however, no one complained.
  • I fail to see your point; furthermore, your entire argument is off the subject.
  • The strike delayed shipment; therefore, your order will not be sent on the date we promised.
  • The train slipped off the track at Innsbruck; the passengers, accordingly, had to continue by taxis.
  • The storm ruined two speakers; the band, however, had spare ones in the van.