Sentences need subjects (actors) and verbs (actions) to function properly; if one or the other is missing, the sentence becomes a fragment and its meaning becomes unclear. Such fragments are not appropriate for most academic writing, as they will confuse the reader and affect the logic of your argument/discussion.
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.
Another problem to avoid is running sentences together without any punctuation (i.e., run on) or trying to join them with a comma (i.e., comma splice), as a reader will not be able to figure out where one idea ends and another begins. Long sentences are fine, as long as they are clearly constructed and punctuated to help the reader through them; however running many ideas together in one sentence haphazardly can cause a reader to stumble over the meaning of the sentence.
An example would be:
The witness described the accident scene as overwhelming, she had never seen so many cars in one heap her head was swimming.
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.
- In this sentence, it is hard to know where one idea ends and another begins. Correct punctuation and some rewording would clarify what is happening and what the witness saw.
Correction:
- The witness described the accident scene as overwhelming: seeing so many cars in one heap made her head swim.
Personal pronouns are a wonderful tool for avoiding the need to constantly repeat the name of a person or group. However, if you do not use them carefully, your reader will have trouble determining who is meant by “she,” “them,” or other pronouns used in the essay. Placing the pronoun “this” at the beginning of a sentence without a clear indication of what “this” means is particularly problematic.
Here are examples of sentences where it is unclear what the pronouns “he,” “them,” and “this” refer to:
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 helps keep the meaning of complex sentences clear, while 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.
The tense of a verb helps readers understand where in time the events or ideas you are discussing or explaining are occuring. 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 a problematic tense switch within a sentence:
Darwin traveled (past) to the Galapagos Islands on his ship, the Beagle, where he observes (present) many varieties of finches. (Note: switch from past tense to present tense is illogical and confusing.)
Click the sections below to learn more about some common sentence structure issues that affect clarity. Also review Creating Complex Sentences located in Resources.