Parallel Construction

When closely related thoughts within sentence are written in similar language structures, the sentences are easier to read. Parallelism is the term for subjects, objects, verbs, modifiers, phrases, and clauses that have similar structures within a sentence.

Parallel clauses: It was the best of times; it was the worst of times.

Parallel phrases: This is a government of the people, for the people, by the people.

Parallel words: The salad contains tomatoes, lettuce, and onions.

Parallelism in Headings and Lists:

Headings and subheadings in technical reports should be in parallel form. Headings must be in the same grammatical form. For example, if giving instructions for a laboratory process requires a set of steps, each with a series of operations, heading for each step should be in the same form as other headings of the same level.

· Making the Gel,

· Pouring the Gel

· Loading the Samples

· Running the Gel.

Parallel construction is useful in giving directions within each step. In the example that follows, each action is described by an active verb followed by a description.

Turn heat to high.

Pour 1 gram of agarose solution into flask, forming a 100 mg sample.

Pour 100 milliliters of 1x buffer (TAE) into flask

Insert a magnetic stirring rod into flask.

Cover the mouth of the flask with cling wrap.

Pierce cling wrap, making a small hole which will prevent pressure build-up.

Place the flask on heat plate.

Turn on magnetic stirrer, ensuring that no clumps of agar form.

Wait for the agar to come to a boil.

Transfer flask to a water bath, preventing solidification.

Parallelism in Sentences and Paragraphs:

Parallelism of words in pairs or triads: Words should be in the same grammatical form:

Example: Taking care of a dog requires time, money, and patience.

Parallelism in comparisons and contrasts: Add a touch of style to your writing.

Example: Dad made his decisions from his brain; Mom made her decisions from her heart.

Parallelism signaled by expressions: Some expressions signal the need for parallel structure. These include:

not only…but also…




on one hand…on the other hand…

Example: We attended both the band concert and the choir program.

Parallelism to show a progression of ideas.

Example: Regular exercise halves the risk of heart disease and stroke, decreases the risk of colon cancer, and reduces the likelihood of osteoporosis. It lessens the chances of developing diabetes and strengthens the immune system. Exercise even helps people overcome depression.

Parallelism used for emphasis. This type of parallelism is particularly effective in long clauses:

Example: If the Democratic Party unifies, candidates will make more effective use of contributions, speeches will reach more voters, and advertising will serve more areas.

Faulty Parallelism: If any segment of the parallel structure does not follow the established language pattern, the flow of the sentence will be interrupted. To correct faulty parallelism, choose one item as the pattern and write the rest to match.

Faulty parallelism: Schools have discipline management plans for two reasons:

to control the unruly student and for the protection of the other students and the faculty.

Correct parallelism: Schools have discipline management plans for two reasons:

to control unruly students and to protect other students and faculty.