Lessons to Develop a Writer's Toolkit:
Sentence Types
Dr. Stuart Blythe
Department of English & Linguistics
Indiana University-Purdue University Fort Wayne
In the previous three lessons, you learned about three building blocks of language: independent clauses, dependent clauses, and phrases. In this fourth lesson, you will learn more about ways to combine these building blocks into sentences. After completing this lesson, you should be able to do the following:
- Identify and produce four types of sentences: simple, compound, complex, and compound-complex.
- Differentiate between characterizing sentences by their structure and by their function.
About Types of Sentences
Sentences can be combined into various different types--from relatively simple ("The assistant weighed the sample.") to more complex ("The assistant, who came to work late, hurried through the procedure because results were due by noon.") These differences may be characterized in terms of structure or function. When you classify a sentence in terms of structure, you do so according to the number and type of clauses it contains. When you classify in terms of function, you do so according to the purpose the sentence serves.
Sentences Classified Structurally
When you classify sentences structurally, you do so according to the number and type of independent and dependent clauses in any sentence. Four types usually appear in language handbooks: simple, compound, complex, and compound-complex.Simple Sentences consist of only one independent clause. Consider two examples:
More mobile phones will become Web-enabled smart phones.
XML (a mark-up language for Web pages) is becoming a key element in many organizations' strategies to cope with the increasing demands for updated, flexible, and usable information products.
Notice that length is not always a reliable factor in classifying sentences. As is the case with the second example, simple sentences can be relatively long if they contain numerous phrases.
Compound Sentences consist of two or more independent clauses. In the following examples, the clauses are surrounded by brackets [ ].
[All soil samples have been taken], and [they have been dried in the lab to remove any remaining water].
[Stan was supposed to collate the data and complete the report on Tuesday], but [the data were unavailable until Thursday].
Note that compound sentences are usually a set of clauses joined by a coordinating conjunction such as and, but, or, so, etc. They may also be divided by a semi-colon. For more on punctuating two independent clauses, see the lesson on punctuation & clauses.
Complex Sentences consist of one independent clause (IC) and at least one dependent clause (DC). Each type of clause is identified in the complex sentences below:
[Although Stan was supposed to collate the data and complete the report on Tuesday (DC)], [the data were unavailable until Thursday (IC)].
[Web developers should develop their proficiency with visual language (IC)] [because Web pages involve as much visual communication as verbal (DC)].
Notice that you use a comma to signal the boundary between an independent and dependent clause ONLY when the dependent clause comes first. See the lesson on punctuation & clauses for more on punctuating independent and dependent clauses.
Compound-Complex Sentences consist of two or more independent clauses (IC) and at least one dependent clause (DC). Each type of clause is identified in the compound-complex sentences below:
[We submitted our calculations (IC)], and [we included several drawings (IC)] [even though both types of information were not required (DC)].
[Even though the data were unavailable until Thursday (DC)], [Stan collated what he had (IC)], and [he submitted the report on Tuesday (IC)].
Sentences Classified Functionally
When you classify a sentence functionally, you do so according its purpose. Whenever you read a sentence, ask yourself, "Why did the writer compose this sentence?" An answer is likely to lead you to a functional classification.
Just as writers of handbooks often identify four structural types, so do they identify four functional types: declarative, interrogative, imperative, and exclamatory.
Writers use declarative sentences to make a statement. For example, "The lab samples will be ready on Wednesday," and, "It may be said that rendering XML documents is tantamount to applying visual language to logical data structures through style sheets," are declarative sentences. Each makes a statement of fact.
Interrogative sentences are used to ask questions. "When are the specifications due?&qupt; is an interrogative sentence.
Imperative sentences express a command. "Enter the data into the spreadsheet," is an imperative sentence, as is, "Submit the revised specifications by Friday." Notice that imperative sentences begin with a verb. The subject (you) is implied. Notice too that imperative sentences are used when describing steps in a set of instructions.
Writers use exclamatory sentences to express strong feelings. "I'm sure glad that project is over!" is an exclamatory sentence. Notice, though, that scientific and technical writers should avoid this type of sentence for the most part because it violates a preference for dispassionate logic.
Why Bother?
Sentence types are worth thinking about because such knowledge can help you combine and vary sentences to good effect. In the lesson on phrases, I presented two sentences:
Wendy will be in New York.
Wendy will await final approval of the contract.If presented in a row, these two sentence would seem choppy, in part because they restate the same subject (i.e., Wendy). When you know how to combine sentences, you know how to achieve a stronger, more readable style--for instance, "Although she will be in New York, Wendy will await final approval of the contract."
Exercises
In order to reinforce this lesson,
- create two examples of each structural type of sentence. That is, create two simple sentences, two compound sentence, two complex sentences, and two compound-complex sentences.
- In the complex and compound-complex sentences, enclose the independent and dependent clauses in brackets. Identify the types of clauses in parentheses.
Examples:
- Complex: [Imperative sentences begin with a verb (IC)] because [the subject (you) is implied (DC)].
- Compound-Complex: [We submitted our calculations (IC)], and [we included several drawings (IC)] [even though both types of information were incomplete (DC)].
last updated: 2003.03.08
originally created: 2001.02.21
© Stuart Blythe | blythes@ipfw.edu