Whenever we write sentences that go beyond pure simplicity, we are already doing "sentence combining."
Let me state that again, this time with no sentence combining:
1. We write sentences sometimes.
2. Sentences [can] go beyond simplicity.
3. [The simplicity I am writing about is] pure.
4. Writing nonsimple sentences is "sentence combining."
5. We are [therefore] already doing it.
Naturally, we like it better the first time, because a bunch of choppy sentences can never make the same degree of sense a well-engineered combination will make. And of course, all of the combining in my example went on behind the scenes in a brief mental flash (although, when I split it up into its five component sentences, the result does rather resemble much student writing).
In order to combine sentences we have already roughly drafted, we need to become aware of some methods for doing so. The most common occurrence is to convert the information in a simple sentence into a dependent clause or some sort of subordinate phrase, which is what happened to 1 and 2 above:
We write sentences sometimes becomes Whenever we write sentences; and Sentences go beyond simplicity becomes that go beyond simplicity.
Sentence 3 collapses into a single word, which gets tucked in before simplicity, and the resulting string of clause-plus-clause introduces the core of the resulting sentence, a combination of thoughts 4 and 5.
Sentence 4's Writing nonsimple sentences simply repeats elements of 1 and 2, so sentence combining can replace the it of sentence 5, which refers to exactly the same thing.
With nine fewer words and four fewer transitions, the result serves the reader much better than those five sentences of weird babytalk could ever do.
A note on vocabulary here: I will be assuming that my readers know what an independent clause is. Sentences that get transformed in ways that change them from independent into dependent or subordinate elements will be referred to as embedded sentences even though they can no longer stand as sentences on their own.
Because my retirement fund is very low (stone-cold empty, in fact), maybe I should ask my students to give me a nickel each time one writes a sentence that might as well have been reduced to a word or two in some other one. If I could get full compliance, I could live handsomely on the proceeds. However, those who wish to save their money may use the following sentence-combining tips.
Using one of the FANBOYS (i.e. coordinating conjunctions) or else a semicolon, one may string together as many as the reader can stand any reasonable number of independent clauses:
Good: My dog has fleas, so she might need a bath, but I have no dog soap, so I'll have to go to the store.
Okay, but not nearly as good: My dog has fleas; she needs a bath; I'm pretty tired right now; let's do it tomorrow.
This might seem too obvious to mention, but see above, regarding me getting rich if I had a nickel every time a student neglects it:
1. Emily Dickinson wrote mostly short poems in simple language.
2. However, Dickinson's poems are often very hard to understand fully.
Combined:
Emily Dickinson wrote poems that are mostly short and simple but often very hard to understand fully. (Note that we do not need a comma before this but).
Or,
1. Lawyers often use passive voice and other evasive turns of phrase.
2. Politicians also frequently use those kinds of evasive language.
Combined:Lawyers and politicians both often use passive voice etc. etc.
(Note that now we are creating embedded sentences instead of working with all independent clauses.)
Two major word groups function to transform independent clauses into subordinate ones: the subordinating conjunctions and the prepositions. (For full lists of these, see a reference work such as Hacker's Rules for Writers.)
Some subordinating conjunctions embed clauses according to cause or effect:
Because my dog has fleas, she needs a bath.
Others unite contrasting or contradictory ideas:
Although my dog has fleas, she seldom scratches.
Still others name their own special relationships:
When my dog gets fleas, she has to live in the garage.
Prepositions themselves name relationships between ideas. Some work well for sentence combining:
If my dog gets fleas, I will have the vet take care of it.
And in the case of same-subject sentences, the embedding can go deeper:
Dogs that get fleas need baths.
A verbal is another kind of embedded sentence: a verb or verb phrase from one sentence used in another one as a modifier.
One common form of this trick turns on the participle. A verb's present participle (in this case, having) can function as an adverb, modifying some other verb, or as a whole-sentence modifier; My dog has fleas can thus transform into Having fleas. These participial phrases can be combined with conjunctions:
Having fleas, my dog needs a bath, but being tired, I don't feel like doing it.
Participial phrases may also be put into the past (a tense we call past perfect, meaning the thing had already happened at some point in the past). In the following, the dog still had the fleas, but I was done working at the time:
Having fleas, she needed a bath; but having worked hard all day, I put it off.
The past participle works a bit differently. (Students of mine have already encountered this verb form as the basis of the passive voice: fleas were had by my dog.)
1. [Someone] beat him half to death.
2. He slowly made his way home.
Combined: Beaten half to death, he slowly made his way home.
(Notice that this usage has a lot in common with the passive: the beaters have escaped from the sentence.)
The participle can also be transformed into a gerund, meaning that it functions as a noun instead of as a verb. Gerund phrases are verbals that look just like participial phrases except that they do not modify the host sentence—they become its subject or object:
As subject: Having fleas cannot be very comfortable.
As complement (i.e. completer) of the verb "to be": My worst nightmare is leaving the stove on and burning down the house.
As direct object: My dog loves digging in the dirt.
As object of a preposition: I often dream about forgetting the combination of my junior high locker.
There are other kinds of verbals, but these are less likely to help us with our sentence combining.