Two Ways to Join Sentences:  Subordination and Coordination
(longer version)

Clauses

 

A clause is simply a subject and a complete (finite) verb, along with its modifiers.  Clauses can either be independent (meaning that it can stand alone as a sentence) or dependent or subordinate (meaning that the clauses must be joined to another sentence).

 

                           Independent:  My dog can catch a Frisbee in her teeth.

Dependent (fragment, wrong): Because my dog can catch a Frisbee in her teeth.

 

Subordination

 

You subordinate one sentence to another when you join two of them together to emphasize the ideas in one sentence or when you want to show a connection between two sentences.  Whenever there is a relationship between two sentences that can be expressed with a subordinator, it is usually best to do it.  Instead of talking about two sentences joined together, it is more customary to refer to one sentence consisting of two clauses.

 

Here is a list of common subordinating conjunctions (“subordinators”):

 

Time:  when, whenever, after, as, before, once, since, till, until, now, that, while, as long as, as soon as.

Concession:  though, although, even though, if, while.

Contingency:  if, once

Condition:  if, in case, as long as, unless provided that.

Reason:  because, since, as long as.

Result:  so, so that.

Comparison:  as, just as, as if.

Contrast:  while, whereas.

 

Subordinate clauses at the beginnings of the sentences are always set off by commas.  When the subordinate clause is second, the meaning of the sentence determines whether commas are used. If the idea in the main clause depends on the idea in the subordinate clause, there is no comma (the default situation); otherwise, there is.  Generally, there is a comma in front of even though and although, but not in front of because and if.

 

Coordination: 

 

You can join two independent clauses with (1) a conjunction, (2), a semicolon,  (3) a semicolon and a conjunctive adverb (adverbial conjunction), (4) a colon, or (5) a correlative conjunction.

 

1.     Coordinating conjunctions (coordinators):  and, or, but, yet, nor, for.  (Use the acronym BOYSFAN to remember them:  But, Or, Yet, So For, And, Nor.)

 

Our family has a cat, and we also have two dogs.

Sophie is a German Shepherd, but Grice is a mixed-breed.

Sophie is not much of a lady, nor is Grice a gentleman.

 

Notice that the subject and verb are inverted after nor; this word requires a negative in the first clause.

 

2.      The Semicolon:  Use to join two sentences when the idea in each is related and when you want to give equal emphasis to both ideas:

 

Sophie is an obedient and responsive dog outside; Grice is aggressive and hard to control.

The dogs generally sleep when we do; they have completely adapted to our schedules.

 

3.      Conjunctive Adverbs and a semicolon:  use to express a relationship between two sentences.  Adverbs can be moved around within the sentence, but a conjunction cannot.  The semicolon is really what is joining the sentence, but the conjunctive adverb can express the relationship between the two sentences. 

 

      With a conj. adverb:  Sophie is a German Shepherd; however, Grice is a mixed-breed.

                                          Sophie is a German Shepherd; Grice is a mixed-breed, however.

                                          Sophie is a German Shepherd; Grice, however, is a mixed-breed.

      With a conjunction:    Sophie is a German Shepherd, but Grice is a mixed-breed.

                          Wrong:    Sophie is a German Shepherd; Grice is a mixed-breed, but.

                          Wrong:    Sophie is a German Shepherd; Grice, but, is a mixed-breed.

 

Here is a list of many conjunctive adverbs:

 

Result:  therefore, consequently, as a result, of course.

Concession:  nevertheless, yet, at any rate, still after all, of course.

Apposition:  for example, for instance, that is namely, in other words

Addition:  moreover, furthermore, also, in addition, likewise, further

Time:  meanwhile, in the meantime.

Contrast:  however, instead, on the contrary, on the other hand, in contrast, rather

Summary:  thus, in conclusion, then.

Reinforcement:  further, in particular, indeed, above, in fact.

 

These special adverbs are almost always separated from the other parts of the sentence by commas.  When they occur in the middle of the sentence, they should have commas on both sides.  When they are at the beginning or end of a clause (sentence used as part of another sentence), they are followed or preceded by a comma.

 

4.      Colons are similar to semicolons, except that with a colon, the second clause further explains or amplifies the first.  It’s as if you were writing the same thing twice, but in different words.

 

5.      Correlative Conjunctions:  these are the types that come in pairs:  either . . . or, neither . . . nor, not only . . . but also.  Note how inversion of the subject and the verb works:

 

Either the dogs pester the cat in play, or they chase him in earnest.

The dogs either pester the cat in play or chase him in earnest.

The cat neither plays with the dogs, nor does he like to sleep with them.

Not only does Grice chase our cat indoors, but he also chases squirrels or any other small animal outside.