Why Varying Sentence Length Engages Your Reader
How long should your sentences be? It depends. How much of your writing do you want your readers to understand?
Shorter sentences increase understanding. The longer the sentence, the less readers comprehend.
A string of long sentences (30+ words) is difficult to digest.
Example
Apoptosis occurs normally during development and aging, as a homeostatic mechanism to maintain cell populations in tissues, and as a defense mechanism in immune reactions or when cells are damaged by disease or toxic agents. (35 words) Although apoptosis can be triggered by a wide variety of stimuli and conditions, both physiological and pathological, not all cells will die in response to the same stimulus. (28 words) Apoptotic death can occur through a p53-dependent pathway as a result of DNA damage caused in cells exposed to irradiation or drugs used for cancer chemotherapy, or be induced by hormones, such as corticosteroids. (34 words)
Alternatively, a message written in a string of short sentences is choppy.
Example
HIV is an incurable infection that causes AIDS. (8 words) Antiretroviral therapy (ART) suppresses HIV to undetectable levels. (8 words) Stopping ART causes the virus to rebound to pretreatment levels. (10 words) To keep HIV suppressed, people with HIV must commit to a lifetime of ART. (14 words) However, ART does not give HIV patients a normal lifespan. (10 words) The therapy causes side effects and does not completely suppress viral replication. (12 words). HIV is also becoming more resistant to drug therapies. (9 words) Thus, ART is not a long-term solution to treating HIV. (10 words)
And a string of medium sentences (15–25 words) is monotonous.
Example
Cardiac repair after myocardial infarction results from a finely orchestrated and complex series of events. (15 words) These events are initiated by an inflammatory phase that digests and clears damaged cells and extracellular matrix tissue. (18 words) This stage is followed by a repair phase that resolves inflammation, fibroblast proliferation, scar formation, and neovascularization. (17 words) The quality of wound healing is determined by the proper function and timing of these phases. (16 words) If the inflammatory phase goes awry, it can cause tissue damage, improper healing, and defective scar formation. (17 words)
Vary Sentence Length to Engage Your Reader
Scientists tend to write medium to long sentences. This habit either hypnotizes readers with boring monotony or challenges their attention and understanding.
Good writing consists of a mixture of short and long sentences. Short sentences have punch and are a great way to emphasize important points. Longer sentences add rhythm to your writing. By using both short and long sentences, you add interest and drama to your writing that keeps your readers’ attention.
Example
The inner lining of blood and lymphatic vessels is composed of a compact single layer of endothelial cells. (18 words) These cells are bound to each other through strong intercellular junctions. (11 words) Similar to the epithelial-mesenchymal transition (EMT), endothelial cells can undergo changes that cause them to acquire a mesenchymal, myofibroblast-like phenotype. (20 words) This process is termed endothelial-mesenchymal transition. (6 words) During this transition, endothelial cells lose their specific markers and intercellular contact proteins, start expressing fibroblast-specific and mesenchymal proteins, and synthesize extracellular matrix. (23 words) These cells ultimately acquire a fibrogenic phenotype, become motile, and can migrate into surrounding tissues. (15 words)
Did you notice that all of the sentences in the previous example contain less than 25 words? The recommended maximum length is 25 words per sentence. By keeping most of your sentences below this maximum, you can keep your reader engaged in your writing.
Writing Challenge
Take a look at your most recent writing project. Count the number of words in each of your sentences. How many of your sentences are more than 25 words? Are your sentences of varying length? What is the average number of words per sentence?
Now go through your writing and shorten some of the long sentences. Make sure each sentence only gives one piece of information. Long sentences typically have more than one point, so breaking them up is a straightforward way to increase the clarity of your message.
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