Sentences have subjects and verbs; lacking one or the other, the writer’s meaning can be unclear. Such fragments are not appropriate for an academic essay. Sentences must normally have both a subject and a verb, that is, an actor and an action. If one or the other is missing, the result is a sentence fragment.
Examples of fragments include:
No verb/action:
- The busy summer streets of Santiago.
- Literary critics with a penchant for bourbon.
No subject/actor:
- That never saw the light of day.
- Turning with little interest and a heavy heart.
At the other extreme, neither should a sentence run on line after line without a period; readers will not be able to keep up. Sentences can be long if they are clearly constructed and punctuated to help the reader through them, but running many ideas together in one sentence haphazardly can easily cause a reader to stumble over the meaning of the sentence.
An example would be:
The lawyer was taken aback by her client’s description of the accident scene where she had not seen that many cars in one heap that her head was swimming.
Personal pronouns are a wonderful tool for avoiding the need to constantly repeat the name of a person or group. However, if one is not careful in their use, a reader will have trouble determining who is meant by “he,” “them,” or other pronouns used in the essay. Particularly problematic is placing the pronoun “this” at the beginning of a sentence without a clear indication of what “this” means.
Here are examples of sentences in which it is unclear what is meant by the pronouns “he,” “them,” and “this”:
Raj looked carefully at Edwin because he had never been this sad. (Who is sad—Raj or Edwin?)
Jelena raised rabbits with her parents, and her teacher asked if she would bring them to school one day. (Who does “them” refer to—her parents or her rabbits?)
When parents try to ignore inappropriate attempts to gain their attention, children often escalate to more extreme tactics. This prompts considerable anxiety. (What prompts the anxiety—trying to ignore the children or the children’s extreme tactics?)
Writing about complex ideas frequently requires building complex sentences with multiple clauses. Punctuation can be helpful in keeping the meaning of complex sentences clear, but errors in punctuation can increase a reader’s problems considerably.
For suggestions about how to keep the relationship between two ideas clear for a reader through correct use of a few simple words, see Creating Complex Sentences located in Resources.
Readers are often confused by changes in verb tense from one part of an essay to another.
Generally speaking, if you start writing a paragraph in the present tense, you should not switch to the past tense or future tense within that paragraph unless doing so aids the communication of your meaning.
Shifting from one verb tense to another anywhere in your essay should only be done when your ideas or argument clearly require it.
Example of tense switch within a sentence:
Darwin traveled to the Galapagos Islands on his ship, the Beagle, where he observes many varieties of finches. (Note: switch from past tense to present tense.)
Click the sections below to learn more about some common sentence structure issues that affect clarity. Also review Creating Complex Sentences located in Resources.