Subject Index - Grammar and Usage

• a and an
• affect and effect
• assure, ensure, and insure
• because and since
• capitalization
• compose and comprise
• criterion, datum, memorandum, phenomenon, and their plurals
• first-person pronouns
• hyphens, compound words, and unit modifiers
• inclusive language
• it's and its
• misplaced modifiers
• nonrestrictive phrases and clauses
• noun and adjective strings
• nouns
• over and under
• parallelism
• personal pronouns
• prefixes
• principal and principle
• race and ethnicity
• restrictive phrases and clauses
• spelling
• that and which
• time
• unit modifiers
• which and that

a and an

Use "a" before any acronym or word that begins with a consonant sound. Use "an" before any acronym or word that begins with a vowel sound. An acronym is pronounced as a word (for example, a HEPA filter); an initialism is pronounced as its letters (for example, an NGO). The first sound of the word or letters indicates whether to use "a" or "an." Examples: a light-water reactor, an LWR; a Human Resources Office memo, an HRO memo; a nongovernmental organization, an NGO; a National Renewable Energy Laboratory subcontract, an NREL subcontract.

affect and effect

"Affect" is usually a verb, and "effect" is usually a noun.

affect (verb):

effect (noun):

These words can be confusing because "affect" can sometimes be a noun (when it denotes an emotion), and "effect" can be a verb (when it means "to bring about").

assure, ensure, and insure

"Assure" means to make sure or give confidence. "Ensure" means to guarantee. "Insure" means to provide or obtain insurance.

because and since

"Because" indicates a cause-and-effect relationship. "Since" indicates a time relationship.

capitalization

1. Proper Nouns

Capitalize proper names. These include the names of government programs, official projects, formal groups, organizations, companies, titles when they precede a name (use lowercase in titles that follow the name), specific geographic areas or features, and ethnic groups.

When referring to NREL, "National Renewable Energy Laboratory" is capitalized, but "the lab," "the laboratory," and "national laboratories" are not.

One exception to this rule is companies and products with stylized lowercase or "camel cap" names (e.g., eBay, iPhone). In these cases, use the company’s or product’s preferred capitalization.

2. Figure Captions, Table Titles, and Section Headings

Figure captions: Capitalize only the first word and proper nouns in figure captions. No period needed (unless there are multiple full sentences).

Table titles and section headings: Capitalize the main words of table titles and headings and subheadings, including the second word in a hyphenated term (e.g., "PV Program Five-Year Plan"). No period needed.

Do not capitalize:

• Articles (e.g., "a," "an," and "the") unless they begin the title or heading
• Conjunctions of three or fewer letters (e.g., "and," "or," "nor," "yet," "so," and "but")
• Prepositions of three or fewer letters (e.g., "for," "of," "on," and "up").

Do capitalize:

• Conjunctions (e.g., "than") and prepositions of four or more letters (e.g., “from,” “with,” “above,” “after,” “down,” “inside,” “over,” and “into”)
  
• "To" as an infinitive (but lowercase as a preposition, e.g., “Scientists Travel to Chile To Engage Utilities”)
• Verbs, including "is" and "are."
  

For journal/conference submissions or other non-NREL publications, follow the style recommended by the professional society or publisher.

3. Titles

Capitalize titles when they precede the person's name. Lowercase titles and names of groups when they follow the name.

4. Trade Names

Capitalize trade or brand names, and include a trademark, copyright, or other symbol only when it's an Alliance-registered trademark. Include the symbol the first time you use the trade name in body text (not in a title, acronym list, or section header); thereafter, you may omit the symbol. Also use superscript for trademark symbols. See the trademark symbols entry for a list of Alliance trademarks.

5. Taxonomic Names

When writing about botanical and zoological divisions, capitalize the names of all divisions higher than species: genera, families, orders, classes, and phyla. Italicize genera, species, and varieties.

After you first mention them (and spell them out), you can abbreviate most generic names followed by species names.

See also captions, fiscal year, geographic regions, headings and subheadings, states and countries, and tables.

compose and comprise

"Composed of" is correct; "comprised of" is incorrect. See the examples below.

criterion, datum, memorandum, phenomenon, and their plurals

"Criterion" is a singular noun (one criterion), and "criteria" is the plural (two or more criteria). "Data" is the plural of "datum." The plural of "memorandum" can be either "memoranda" or "memorandums." "Phenomenon" is singular, and "phenomena" is plural.

first-person pronouns

See personal pronouns.

hyphens, compound words, and unit modifiers

Hyphenation rules can be intimidating, but remember that the ultimate goal is to provide as much clarity and consistency as possible. If you can’t find the proper hyphenation in this style guide, consult the AP Stylebook, followed by Merriam-Webster.

1. Verb Phrases: Verb, Noun, and Adjective Forms

Verb phrases that contain an adverb (e.g., build up, set up, start up, and break down) are usually written as two words. The noun and adjective forms of these words are usually one word, although there are exceptions.

2. Compound Words Containing Prefixes and Suffixes

In most cases, you don't need a hyphen between prefixes or suffixes and the root words.

Exceptions: 
Sometimes hyphens are needed when the root word begins with the same letter that the prefix ends in.

Use a hyphen between prefixes and proper nouns (but not common nouns) or dates whether they're used as nouns or modifiers.

Use two hyphens when adding a prefix to a word that already contains a prefix, even when there is no hyphen after the prefix in the original word.

Finally, these prefixes usually require a hyphen: "ex," "self," and "quasi."

3. Unit Modifiers With and Without Hyphens

Use a hyphen to indicate that words have been combined into a unit modifier, which is a descriptive expression composed of two or more words that form one new meaning. For example, in the term "flat-plate collector," "flat-plate" is the unit modifier. Here are some examples of unit modifiers that usually include hyphens:

To see how adding the hyphen can prevent confusion, consider these examples:

In the first example, the scientists might seem to have tested a defect; in the second example, it's clear that they tested a gas.

You don't need a hyphen in common unit modifiers that are not ambiguous or confusing.

Don't use a hyphen when both words of a unit modifier are capitalized.

Leave out the hyphens if you rewrite a sentence so the words in the unit modifier come after the noun they describe

Don't use a hyphen with a unit modifier containing an adverb ending in "-ly."

Don’t use a hyphen with two-word Latin phrases when the phrases are used as modifiers.

When you use numbers in unit modifiers, retain all the necessary hyphens.

Or rewrite the sentence to omit the hyphens.

Use suspended hyphens when your compound modifier is interrupted by another word, such as part of a list.

Suspended hyphens can also be used for different prefixes on the same root word (micro- and mesoscale), but the preferred style is to write out each word fully (microscale and mesoscale). Use your best judgment, considering both the context and audience.

4. Common Hyphenated Terms

Certain words and phrases are always hyphenated, regardless of context. Examples include:

inclusive language

The way we communicate reflects our priorities as a laboratory; using inclusive language is respectful and promotes equity. Following are brief discussions of common topics related to inclusivity—please use this as a starting point as you examine the words that you use and their impact. 

Race 

The race and ethnicity entry covers capitalization, hyphenation, and word choice. Beyond that, be mindful of terms and phrases with racist histories—these can be prevalent in both scientific writing and everyday language.

All written, audio, and visual products at NREL must comply with Section 508, which allows assistive technology (e.g., a screen reader) to relay information to a person. Visit the 508 compliance entry to learn more about captions, alt text, and clear navigation of PDFs, webpages, and more. 

Also, take care to avoid using unintentionally ableist language. Examples like “blind to,” “fall on deaf ears,” “crippled by,” and so on imply that people with these disabilities are ignorant or helpless. Instead, reword your sentences to be specific and clear with what you are trying to convey.

Gender 

Whenever possible, use words that apply to any gender, such as “moderator” rather than “chairman” or “manufactured” rather than “man-made.” In addition, honor the pronouns that a person has chosen to describe themself. Note that the nongendered “they” is appropriate in reference to a single person or a group of people; further, “they” is preferred over “he/she,” which often feels cumbersome in text and is less comprehensive.  

The AP Stylebook has entries on inclusive storytelling and gender-neutral language. 

Sexuality, Age, Religion, and Socioeconomic Status 

Be mindful in your writing to not assume victimhood or inadvertently apply stereotypes. For example, rather than “poverty-stricken,” use “low-income.” Instead of “elderly,” use “older adults.” Avoid “the” descriptors (e.g., “the homeless,” “the poor”) because they are usually dehumanizing. Also, when considering identity-based descriptors such as sexuality, age, or religion, consider whether the descriptor is appropriate to include. If it is not relevant to the story, there are often more neutral ways of describing a person or group. 

Inclusiveness Check 

Microsoft Word offers an inclusiveness check as part of its proofing options. However, similar to how spell-checkers do not replace review by an editor, this inclusiveness check does not replace common sense regarding eliminating biases and promoting respect. To turn on this inclusiveness check, go to File > Options > Proofing, click on the “Settings” button next to “Writing Style,” and check all the boxes under the “Inclusiveness” heading. 

Other Resources

There are many resources available about inclusive language and promoting diversity and equity in your writing. Following are a few that may be helpful:

Centers for Disease Control and Prevention. 2022. “Preferred Terms for Select Population Groups & Communities.” https://www.cdc.gov/healthcommunication/Preferred_Terms.html.

Ferguson, Jackie, Kaela Kovach-Galton, and Roxanne Bellamy. 2020. Say This, Not That: Activating Workplace Diversity Through Inclusive Language Practice. The Diversity Movement. https://thediversitymovement.com/wp-content/uploads/2020/11/WW-SayThis-whitepaper_201116-F.pdf.

Google. 2021. “Striving for a more inclusive workplace? Start by examining your language.” https://www.thinkwithgoogle.com/intl/en-ssa/future-of-marketing/management-and-culture/diversity-and-inclusion/diverse-workplace-inclusive-language/.

Inclusive Naming Initiative. 2023. “Frequently Asked Questions.” https://inclusivenaming.org/faqs/.

Lawrence Livermore National Laboratory. 2022. Pronouns Matter Everyday. LLNL-BR-831843. https://www.llnl.gov/sites/www/files/2022-03/Pronouns_Matter_%2020220308.pdf.

Linguistic Society of America. 2016. “Guidelines for Inclusive Language.” https://www.linguisticsociety.org/resource/guidelines-inclusive-language.

Questions can be directed to the Editorial Board or the Office of Diversity and Inclusion.

it's and its

Even though "it's" has an apostrophe, it isn't a possessive pronoun. "It's" is a contraction, a short form of two words, like "isn't." "It's" always means "it is." "Its" is the possessive form of "it." Like "his," "hers," and "ours," the possessive "its" never needs an apostrophe.

misplaced modifiers

Modifiers in the wrong place can make a sentence confusing.

In this example, it isn't clear who or what identified the correct material. This might be better: After identifying the correct material, we conducted the 5-minute test procedure.

What, or who, was lost—the manuscript, the woman, or the reader? Try to keep modifiers as close as possible to the people and things they describe. Strunk and White, authors of The Elements of Style, say this: "Modifiers should come, if possible, next to the word they modify." This is especially true for sentences containing introductory prepositional phrases or clauses followed by a comma.

nonrestrictive phrases and clauses

A nonrestrictive phrase or clause is one that adds information but is not essential to the meaning of the sentence.

Nonrestrictive or nonessential phrases and clauses are enclosed between two commas when the phrase or clause is within a sentence, and they usually begin with "which" rather than "that." See also restrictive phrases and clauses and which and that.

noun and adjective strings

Try not to string too many nouns and adjectives together in a sentence. An "agency personnel communications interface display" could also be called a "display of the communications of the agency's personnel." Better yet, it could just be called the "staff bulletin board."

nouns

To give your writing more flow and vigor, try changing some of the nouns (especially those ending in -tion and -ment) to verbs (e.g., determine, complete, accomplish, achieve, measure, convert, characterize, combine) and other parts of speech. Doing this will move your readers along more quickly and make it easier for them to understand your text. In these examples, we changed some of the nouns in the first sentences to verbs and other parts of speech.

Which sentences were easiest to read and understand?

over and under

In cases involving quantity, use "more than" rather than "over," and use "fewer than" or "less than" rather than "under." In cases involving temperature, use "higher than" or "lower than" or "warmer than" or "cooler than." In cases involving weight, use "heavier than" or "lighter than."

parallelism

Use parallel construction in sentences as well as in lists. Express all similar sentence elements (subjects, verbs, verbals, objects) in a similar way.

personal pronouns

First-person pronouns may be used in technical communications when appropriate, and some scientific and technical associations (such as the American Institute of Physics) encourage technical writers to do so. Common first-person pronouns include "we," "our," and "us." Personal pronouns can prevent confusion by clearly and concisely showing who performed an experiment or procedure.

Which of the following two sentences is easier to read and understand quickly?

See also active voice and passive voice.

prefixes

See hyphens, compound words, and unit modifiers and scientific notation.

principal and principle

"Principal" often means "chief" or "main," such as the principal investigator in a research project or the principal of a high school. "Principle" often refers to a belief, value, or rule.

race and ethnicity

As a laboratory that strives for diversity of perspectives and inclusivity, our word choices, style, and tone must be carefully considered, particularly when it comes to topics related to race and ethnicity.

Capitalize Black when referring to African Americans or, more broadly, in any racial, ethnic, or cultural sense; do not capitalize white. Do not use the terms “Black(s)” or “white(s)” as singular or stand-alone nouns referring to a person or people. In the plural form, “Black people,” “white people,” “Black scientists,” and “white scientists” are preferable when clearly relevant.

Capitalize “Indigenous” in reference to original inhabitants of a place, aligning with long-standing capitalization of other racial and ethnic identifiers such as Latino, Asian American, and Native American. (Note that no hyphen is used in dual heritage terms such as “Asian American” and “Mexican American.”) Capitalize “Elder” when referring to a Tribal or religious leader, but lowercase it when used to identify someone by age or when used generally.

The terms “Tribal” and “Tribe” should be capitalized, even when they are not part of an entity’s official name. Capitalize the word “nation” when part of a formal name.

In Alaska, the Indigenous groups are collectively known as Alaska Natives. Both “American Indians” and “Native Americans” are acceptable terms when referring to two or more people of different Tribal affiliations. “First Nation” is the preferred term for native Tribes in Canada. “Indian” is used to describe the peoples and cultures of the South Asian nation of India and should not be used as shorthand for American Indians, unless that is how a particular group prefers to be referenced.

For additional details, refer to the AP Stylebook's race-related coverage.

restrictive phrases and clauses

Do not use commas around restrictive phrases and clauses. They are essential to the meaning of the sentence, in contrast to nonrestrictive phrases and clauses, which simply add information that is not essential.

See also which and that.

spelling

If you can't find a word or phrase in this style guide, consult the following reference guides in this order: (1) The Associated Press Stylebook and (2) Merriam-Webster's Collegiate Dictionary, Eleventh Edition.

For spelling out numbers, see numbers.

that and which

See which and that.

time

unit modifiers

See hyphens, compound words, and unit modifiers.

which and that

Standard American English uses "which" for nonrestrictive or nondefining phrases and clauses and "that" for restrictive or defining phrases and clauses. The word "which" usually signals the approach of added, nonessential information. When a phrase or clause is not essential to the meaning of a sentence, use the relative pronoun "which" and enclose the phrase or clause in commas. See also nonrestrictive phrases and clauses and restrictive phrases and clauses.

When a phrase or clause is essential to the meaning of a sentence (that is, the sentence would not make much sense without it), use "that" and leave out the commas.