The Three Types of Sentences

It is often said that writing is rewriting, that our first draft is rarely the final one. And if that’s true (and it is), then understanding the structure of the sentences we’ve managed to put down in the first draft can help us in finding the final best expression of our thoughts and ideas for the reader we are addressing.

English grammar organizes the many different styles of sentences that are possible into three (sometimes four, but three suffices) basic types: simple, compound, and complex. Which of these categories any particular sentence falls into is determined by the number and kind of clauses the sentence has. A clause, we remember, is a group of words with a subject and verb, and when we say something (by means of a verb) about something (the subject), we succeed in stating a thought. A sentence, then, which is traditionally defined as a group of words that expresses a complete thought, really has as many thoughts as it has clauses.

A simple sentence has only one clause. The sentence I bought a new car last week is a simple sentence because it comprises only one combination of subject and verb, I bought. A simple sentence, however, does not necessarily mean a short sentence. The statement After spending a fortune in repairs and getting a warning from my boss about being late yet again, I bought a new car finally last week from that dealer down the street remains a simple sentence; all of the additional phrases before and after the one clause I bought a new car certainly elaborate that one thought, but they do not change the essential framework of the sentence.

But a sentence can express more than one complete thought, and if it does, it’s defined as a compound sentence. So, I ironed some shirts and then I made some lunch states two thoughts because it contains two clauses: I ironed and I made. And as with the simple sentence, the subject and predicate of a compound sentence (the predicate being the part of a clause that contains the verb and any other words the verb needs) can be elaborated: Tired of wearing the same old clothes, I ironed some shirts and then I made some lunch, hungry from all that housework. Not the most graceful of sentences, but still compound in its structure.

Both the simple and compound sentence carry complete thoughts in what are called independent (or main) clauses. An independent clause, as we would expect, stands alone without grammatical connection to another thought in the same sentence or elsewhere in the paragraph. But not all clauses are independent. Some clauses are subordinate (or dependent), made so by a subordinating conjunction (because, if, although, for example). In the sentence After I bought a new house, my property taxes increased 25%, the first clause, with the subject and verb I bought, is subordinate because it depends upon the clause that follows for its meaning to attach to something; saying or reading the subordinate clause alone produces only confusion, not comprehension. Given all this, a sentence that includes at least one independent clause and at least one subordinate clause is termed complex.

So when you take up your draft in revision and find a sentence that isn’t getting your idea across with the clarity or force you intended, pause to determine first the type of sentence you wrote. Then do the same with the sentence before it and after it. Isolate the clauses to see the thoughts you’re expressing, and then redesign one or more sentences to change the organization of the clauses: maybe two simple sentences should be combined into one compound sentence, or perhaps a complex sentence should be reduced to a compound or two simples. This is the basic work of revision, and one of the reasons it is true that writing is rewriting.


A reminder, too, that the second Writing Smartly seminar, Writing a Good Sentence, will be held tonight, October 13, from 7:00 to 8:00 p.m. This one-hour discussion will review the fundamental structure of every well-written sentence and explain how to sharpen the focus of a statement by examining its subject and verb: an exact noun, a strong verb, and fewer prepositions make for clear and compelling sentences. Participants will receive a handout that summarizes the presentation. You may enroll now directly through this registration link. Tuition is $25.



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