Main Body

3.2 Mechanics and Grammar

Writing correctly is vital to being an effective communicator. Errors like misspellings, subject-verb agreement, and incorrect punctuation are distracting to your reader, making it less likely that your communication will achieve its purpose. Your reader won’t likely notice correct grammar (correctness is expected), but they will notice errors. Incorrect grammar reflects poorly on you as a communicator.

Your reader won’t likely notice correct grammar… but they will notice errors. Incorrect grammar reflects poorly on you as a communicator.

As discussed in Engineering Your Writing Process, the review and revision process is essential to producing clear, correct writing. You need to give yourself time to “re-see” your own writing and be able to spot the errors.

To get better at this, try to predict your mistakes. When you receive feedback on your writing, you need to be able to not just correct the errors that were marked, but recognize patterns and weaknesses so you can learn and improve in the future. Become aware of the types of mistakes you tend to make and focus your effort on correcting those issues:

  • Observe and reflect. Carefully review feedback you receive on your writing in FE/FEH and other classes or experiences. Do you see any patterns? Any repeated comments or corrections? What issues are most challenging for you to see in your own writing?
  • Learn and develop. Work to understand the problem areas—read, look at examples, rewrite things you have written in the past. Visit the Writing Center and ask for coaching on the topic.

There are an incredible number of excellent resources online and on campus available to help you address grammatical and mechanical writing issues. As you start to learn how to write in college and in the engineering discipline, make it a priority to fill in any gaps in your skills.

The topics outlined here frequently affect students beginning to write in a technical communications style.


The “tense” we write in indicates to our reader when something happened—past, present, or future. These subtle differences carry important distinctions.

Past: I provided the report. (I sent it to you last week.)
Present: I am providing the report. (It’s attached to this email.)
Future: I will provide the report. (I am still working on it and will send it soon.)

This might seem easy and it typically is intuitive for people fluent in a language, but in technical communications and the complex documents you will write (often as a team), it is important to be aware of tense and use it consistently and correctly in the right places.

Past tense is most common for the engineering technical communications you do in FE and FEH because you are reporting activities that already happened—describing a procedure, lab, research process, or results of an experiment or test. Be consistent with tense as you describe what you and your team did and what your findings were.

Present tense is logical and acceptable for writing emails or communicating with a public audience on your website. In lab reports, present tense might be used to define problems in the Introduction or in making recommendations in the Conclusion (“The team recommends…”).

Future tense is necessary when describing next steps and upcoming planned activities in progress reports, and might also be useful in emails when describing what you will do next.

Parallel Structure

Parallel structure or parallelism is about maintaining grammatical consistency in lists. In a list, you are essentially creating a set of things for comparison and those things should be of a similar type to make the comparison useful.

It is easiest to see in simple sentences:

Not parallel: I like to bike, play baseball, and skiing.
Parallel: I like to bike, play baseball, and ski.
Parallel: I like biking, playing baseball, and skiing.

When writing a formatted list, the same rule applies. A list requires a clear lead-in and then all listed items must be the same grammatical form.

This list maintains clear parallel structure:

For the camping trip, I am packing the following:
– Tent
– Sleeping bag
– Bug spray
– Bottled water
– Camping stove

But this list includes varying grammatical forms:

On the camping trip, I want to do the following activities:
– Hiking
– S’mores [Noun instead of a verb—should be “Making s’mores” to be parallel with the first item]
– Go stargazing [Different verb form that the first list item—should be “Stargazing”]

It is easier to make mistakes with parallel structure as sentences get more complex because you lose the connection to the “lead-in.” Edit sentence and bullet point style lists carefully for parallel structure.

Example: Editing for parallel structure

This memo contains an overview of the lengths of pipes by themselves and with their fittings, a sketch of the finished roller coaster that met all lab requirements, analyzes how well built the roller coaster was, and explains the challenges that were experienced while executing this lab.

Visualized as a bulleted list to make the grammatical comparison easier to see:
This memo contains
– an overview of the lengths of pipes by themselves and with their fittings,
– a sketch of the finished roller coaster that met all lab requirements,
– analyzes how well built the roller coaster was, and
– explains the challenges that were experienced while executing this lab.

NOTE: The first two are nouns and make sense following the phrase “This memo contains…,” but the next two are verbs, so they don’t maintain parallel structure or logical grammar. You would never say “This memo contains analyzes…” and formatting as a list helps make that error clear.

Revised so all the listed items are nouns:
This memo contains an overview of the pipe lengths alone and with their fittings, a sketch of the finished roller coaster that met all lab requirements, an analysis of the quality of the roller coaster’s construction, and an explanation of the challenges experienced while executing this lab.


A paragraph is not just an arbitrary collection of sentences, but a meaningful set of information. Learning how to paragraph effectively will help you move from an outline to fully written document and develop better organized, coherent documents.

Paragraphs should be focused on one main idea. Ideally, all the sentences in a paragraph should work together to explain and build on the idea in the topic sentence (typically the first sentence).

Another way to think about the role of a topic sentence in a paragraph is that they put the “bottom line up front” (or BLUF). Rather than giving your reader all the details before you tell them what the point is, the topic sentence states the main idea, then fills in the supporting information. Topic sentences need to be meaningful and specific—they should contain specific keywords and present an idea that can be developed further in the paragraph instead of vague, placeholder language. For instance,

  • Avoid: The team reviewed the results.
  • Better: The team reviewed the testing results to understand the design efficiencies.
  • Avoid: It is necessary to change the process.
  • Better: It will be financially beneficial to change the product testing process.

In general, paragraphs should be short and focused. There is no absolute “rule” about paragraph length, but 7-10 lines on the page is typically a reasonable range for most document formats. If you see a paragraph that stretches on much longer than that, it likely contains more than one main idea and could be broken up into two or more better focused paragraphs.

Paragraph Cohesion

Cohesion refers to the degree to which a reader can follow the logical progression of ideas developed in a given piece of writing. We can talk about cohesion at the level of a paragraph, a document section, or an entire document.

But how is cohesion achieved? Cohesion occurs when the reader can easily resolve, from sentence to sentence or section to section, the relationship between

  • the given information (what they already know)
  • and the new information.

This becomes more difficult when the information is more technical in nature, so make use of the following strategies to increase cohesion:

Transitions: Transitions are words, phrases, and sometimes entire sentences that act as logical bridges between ideas developed in one sentence, paragraph, section, or document, and another. It’s important to note that transitional devices are not interchangeable, but rather, they signal to your reader how you want them to interpret the relationship between what has come before, and what will come after. Therefore, when making a comparison between two things, it’s appropriate to say “on the other hand…” but if you were summarizing or concluding a section, you would select a different transitional device, such as “consequently,” or “as I have shown…”. See more about useful transition words here. [Link to “Well Organized”]

Threading words: Threading words can clarify connections among topics and actions in sentences and paragraphs expressing complex ideas. Threading words include the following types:

  • Repetition of key terms can be particularly useful when referring to a sequence of events that involve multiple, complex steps with technical names. Repeating the terms helps the reader keep track of the development of the paragraph’s subject and actions.
  • Synonyms for the key term and pronouns (it/they) can also enhance cohesion, and are helpful when you want to avoid beginning each sentence with the same construction or style.
  • Demonstratives (this, that, these, those) can also help clarify which topic/subject from the previous sentence or paragraph that you are referring to in the following new sentence/paragraph.


Topic sentence states a main idea or “claim.” The idea is meaningful and specific.

Supporting sentences clearly relate back to the claim presented in the topic sentence, adding detail and explaining.

Sentences connect and build on each other, moving from a general statement about the value of communication skills, through the benefits to their future academics, and then career tracks.

This serves as a transition to guide the reader’s focus from academics to their future career.


Sample Paragraph

Technical communication skills are valuable for first year engineering students. Writing in an engineering or scientific context might be new for these students, but emphasizing communication skills at the start of a student’s academic career will help them perform well in their degree program. Engineering students must develop effective written and verbal communication skills alongside their technical skills. Beyond academics, these skills will support students’ future career development and advancement in or out of the engineering field, allowing them to not only have innovative ideas, but to share and promote them successfully.

Examples: Well-structured, coherent paragraphs

The context of a document is often needed to fully assess the effectiveness of a paragraph, but these paragraphs generally show good attention to BLUF and adequate development.

The experiment showed that increasing the size and quantity of propeller blades increased the power output of the turbine. The three-blade manufactured propeller produced 0.25 W, while the two-blade propeller produced 0.12 W. Design 2 produced 10% more power than the smaller Design 1 (see Table 3), suggesting that blades with a larger surface area may produce more power. 30 degrees was the more powerful pitch tested, producing 5% more power than the 45 degree pitch (Table 5).


The team will use concept scoring to evaluate whether the team should move forward with their design changes. Concept scoring allows qualitative factors to be compared systematically. The matrix will be used to score each design on criteria from the mission concept review. These criteria scores will be compared to determine whether the team’s design changes are aligned with the client’s priorities. To increase accuracy of results, designs will be scored in a set of trials. This process will clarify the differences between designs.


The specific heat of the unknown metal was determined to be 0.242 cal/g°C. Using the values obtained for the energy released by the metal and the change in temperature of the metal, equation 3 was used to calculate an experimental specific heat.

[latex]C = \frac{Q}{m \Delta T}[/latex] Specific heat (cal/g°C) = energy lost (cal)/ mass(g) * change in temperature (°C) (3)

The experimental values are shown in Table 4 (see Appendix C for sample calculations).

Table 4. Experimentally determined specific heat values

Trial Specific Heat (cal/g°C)
1 0.241
2 0.244
3 0.242

The average of the experimental values was 0.242 cal/g°C with a standard deviation of 0.00153.


The data suggests that vehicles on Woody Hayes Drive consistently travel 4-5 mph faster than the posted speed limit. The speeds of all cars observed can be found in Table A3. The data set indicated with strong central tendency and low dispersion that the typical vehicle speed on this section of Woody Hayes Drive was between 29 and 30 mph. This value was reasonable, given the posted speed limit of 25 mph.

Practice & Application: Exercise G – Logic, Cohesion, and the Bottom Line



Key Takeaways

  • Readers care about grammar and correct writing, even though grammar is not the only requirement for effective writing. Incorrect or messy grammar and mechanics will undermine your authority.
  • Pay attention to patterns of grammar or mechanical issues in your writing and work to improve them—seek feedback and resources that will help you.
  • Use tense consistently and correctly—past tense is most common in lab-related writing for FE and FEH.
  • Be consistent when writing lists—all items in a list should have the same grammatical form (parallel structure).
  • Give paragraphs a clear main idea or “claim” that is clearly stated in a topic sentence and developed in the supporting sentences.

Additional Resources

Center for the Study and Teaching of Writing – Writing Mechanics handouts
Parallelism (parallel structure)


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Fundamentals of Engineering Technical Communications Copyright © by Leah Wahlin is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.

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