Appendix E: Sentence Structure
When building anything, it is important to be familiar with the tools you are using. Grammatical elements are the main “tools” you use when when building sentences and longer written works. Thus, it is critical to have some understanding of grammatical terminology in order to construct effective sentences. If you would like to a review some basic parts of speech (nouns, pronouns, articles, adjectives, adverbs, verbs, conjunctions, prepositions, etc), see the Parts of Speech Overview at the OWL.
The two essential parts of a sentence are the subject and the predicate (verb portion). The subject refers to the topic being discussed while the verb conveys the action or state of being expressed in the sentence. All clauses must contain both a subject and a verb; phrases, on the other hand, lack one or both a subject and a verb, so they need to relate to or modify other parts of the sentence. Main clauses, also called independent clauses, can stand on their own and convey an idea. Dependent clauses, also called subordinate clauses, rely on another part of the sentence for meaning and can’t stand on their own.
Consider the following examples:
| Independent Clause | Phrase |
|---|---|
| The engineers stood around the table | looking at the schematics for the machine. |
| (subject) (verb) (phrase) | (phrase) (phrase) |
Sentence 1 is a simple sentence. It has one clause, with one subject (The engineers) and one verb (stood). These are followed by 3 modifying phrases (“around the table” “looking at the schematics” and “for the machine”).
| Dependent Clause | Independent Clause |
|---|---|
| After they discussed different options, | they decided to re-design the components. |
| Sub. Conj. (subject) (verb) (phrase) | (subject) (verb) (phrase) |
Sentence 2 is a complex sentence, with one dependent and one independent clause, each with its own subject-verb combination (“they discussed” and “they decided”). The two clauses are joined by the subordinate conjunction, “after,” which makes the first clause subordinate to (or dependent upon) the second one.
Being able to identify the critical parts of the sentence will help you design sentences that have a clear and effective subject-verb relationship. Knowing the components will also help you improve your punctuation. If you would like a more detailed review of sentence structure, visit Purdue’s OWL (Online Writing Lab) Mechanics page.
Sentence Structures
There are four main types of sentence structures: simple, compound, complex, and compound-complex. In the examples above, Sentence 1 is a simple sentence, while Sentence 2 is complex.
SIMPLE SENTENCES have one main clause (one subject + one verb) and any number of phrases. The following are all simple sentences:
Sample simple sentences
- A simple sentence can be very effective.
- It makes one direct point.
- It is good for creating emphasis and clarity.
- Too many in a row can sound repetitive and choppy.
- Varied sentence structure so