I have an embarassing confession to make: After decades of writing in English (and years of teaching scientific writing), I still struggle with possessives. A possessive is the ‘s or the of that you put between two nouns to indicate that the second belongs or is related to the first, such as in “Pee-wee’s Big Adventure” or “The Father of the Bride.” Presented like that, it sounds easy, but in scientific writing, there are countless situations in which it’s unclear – at least for me – whether one should use the ‘s, the s’, of, or nothing at all.

For example, would you say “the cell’s nucleus” or “the nucleus of the cell”? And what would you call the discovery of the DNA double helix by Watson and Crick? Watson and Crick’s discovery of DNA double helix? Or Watson and Crick’s DNA double helix discovery? And what about using et al.? Should you put an ‘s afterward? It’s confusing, isn’t it?

But fear not, my dear reader, I’ve decided to investigate this possessive mess and report the fascinating results of my research. In this post, I’ll describe the different forms of possessives and how to use them. Next, I’ll shed light on using possessives in cumbersome scientific formulations, such as after a long series of authors or with “et al.” Get ready for the plunge!

What is the possessive, and what are its different forms?

In English grammar, a possessive indicates ownership or a relationship between one thing and another. You can form possessives in several ways:

1. The Saxon genetive ‘s: Contrary to what its name suggests, the Saxon genitive has nothing to do with the private parts of a medieval Englishman. The Saxon genetive refers to the apostrophe and the “s” at the end of a noun to indicate belonging. For example, in “King Arthur’s testicular gland,” the ‘s added to “King Arthur” indicates that the testicular glands belong to him.
2. The preposition of: Of is a favorite word in English, especially in academic writing. It is used to describe complex structures and relationships, as in “Survival of the Fittest.”
3. The zero possessive: The zero possessive evokes the personality profile of a polyamorous candidate from Temptation Island, but that’s not what it’s about. With the zero possessive, you don’t add anything to indicate possession, as in ” The department head.”

What is confusing with possessives is that, in many cases, there isn’t a clear rule that tells which one you should use. The choice between one form or the other is often subjective and more a matter of stylistic preference than strict grammatical correctness. But there are a few guidelines that can help you make your choice. Let’s take a look at them!

When to use the ‘s?

The Saxon genitive is typically used for animate subjects, whether people or animals. The ‘s signifies that something belongs to someone, such as in “Marie Curie’s first laboratory.”

You can also employ the Saxon genetive for animals, as in “the rat’s neurological response.” The ‘s then implies an intimate or direct relationship between the animal and the object or phenomenon in question (in that example, the neurological response).

The ‘s stands for possession in a broad sense

In scientific writing, the possessive ‘s often goes beyond simply indicating ownership in the physical sense. You’ll often find it used to identify the author, discoverer, or developer of a theory, concept, or research.

For example, “Einstein’s theory of relativity” doesn’t mean that Einstein owns this theory but rather that he developed it. Similarly, “Hawking’s research into black holes” emphasizes the essential role played by Stephen Hawking in advancing understanding of these cosmic phenomena. In other words, you can use the Saxon genetive ‘s to attribute scientific ideas to their authors.

What if the noun finishes with an s?

If the noun ends with an s, instead of adding another s after the apostrophe, simply add the apostrophe to the end of the existing s.

You may need to do this with plural nouns ending in s, such as “the participants’ physiological responses,” as well as with singular nouns ending in s, such as “Dawkins’ handbook.”

What if you want to refer to several persons or an institution?

The Saxon genitive also designates possession by several people. Add the ‘s to the end of the last noun in the series, as in “Watson and Crick’s discovery of the double helix.” Here, the ‘s indicates that Watson and Crick jointly made the discovery.

Finally, you can also use the Saxon genitive to refer to a team or institution, such as in “NASA’s telescopes,” “the university’s psychology department,” or “Harvard’s curriculum. “

The ‘s as a tool for animating the inanimate

The Saxon genitive ‘s introduces a layer of personalization and creates an intimate bond of possession or association. That’s why it’s mainly used with people and animals. But you will also find it associated with inanimate objects and abstract concepts. The ‘s possessive then lends them a touch of life, almost a personal nature. For example, if you write “computer’s hard drive,” you subtly imply that the computer, like a living entity, may possess or hold something of its own.

In conclusion, the Saxon genitive reflects the dynamic nature of the English language, where even possessive constructs become vectors for creativity, personalization, and deeper meaning.

When to use of?

Of can imply possession, belonging, or origin. It differs from the Saxon genitive ‘s in that of is mainly used for inanimate objects or abstract concepts and often sounds more formal.

Prefer of for inanimate objects and abstract concepts

The preposition of is typically used when the possessor is an inanimate object.

For example, one would rather say “The structure of the solar system” than “The solar system’s structure.” Similarly, “The calibration of the equipment” seems more natural than “The equipment’s calibration.”

The of construction is also usually more appropriate for dealing with abstract concepts. For example, “The significance of the findings could change our understanding of genetics” rather than “The findings’ significance could change…”. And “The effects of climate change” sounds better than “Climate change’s effects.”

Of is great for avoiding confusion in a long or complex sentence

Scientific papers are as infamous for their long and complex sentences as doctors are for their indecipherable handwriting. If you can, it’s best to avoid wordy sentences, but sometimes it’s just not possible. In these cases, it is often judicious to use of instead of ‘s even if these sentences involve an animate subject such as a person or a team. For example, “The results of a study conducted by an international research team” flows better than “An international research team’s study results.“

Similarly, if you have to write a sentence with several possessive forms, use of to avoid repeating ‘s. For example, “The approval of the University’s ethics committee” is clearer than “The University’s ethics committee’s approval.”

Use of creates a more formal impression

The possessive of gives a more formal aspect to a sentence. For example, “The head of the institute” is slightly more formal than “the institute’s head. ” That’s why of formulations are frequently used in scientific articles, official documents, formal speeches, and contexts that require a more structured, traditional tone.

Put in simple words: The of introduces a certain distance that suits formal settings, while the ‘s communicates a more direct and familiar tone, which may be preferred to create a conversational ease.

When you don’t use any possessive marker: The zero possessive

The zero possessive is a way of showing belonging without using additional words. By putting two nouns together, one understands that they relate to one another. Academic papers are full of zero possessives, such as “Literature review,” “Peer review process,” “Sample size,” “Quantum mechanics,” “Market analysis,” “Legal framework,” “Cell structure,” “Data analysis,” “Response time,” “Geometry theorem,” or “Molecular structure.”

Here again, there isn’t a strict rule to decide when to apply the zero possessive, but you will find it mostly when:

1. The two nouns are commonly used together. Here, I’m talking about expressions that you hear all the time, such as “Research methodology,” “Data processing,” or “Protein synthesis.” These phrases are so common that you could say the first word (e.g., “evolution”), and the second (e.g., “theory”) would automatically pop into your readers’ minds.
2. The two nouns form the subcategory of a larger category. For example, “Laboratory equipment” is a sub-category of the broader “Equipment” category. Similarly, “Electron microscopy” refers to a subtype of microscopy.

In short, use the zero possessive when the two nouns are so obviously linked to each other that their association seems to constitute an expression, a compound word in itself.

Possessive dilemmas in science

Which possessive should one use at the boundary between animate and inanimate? Organs, cells, fungi, and other borderline nouns

Entities like organs, cells, genes, yeast, mushrooms, viruses, and other bacteria blur the line between animate and inanimate. So, which possessive should you use for them?

Here again, there is no simple rule. The forms you choose will depend on the clarity and fluidity they bring to your sentence and the formality of the style you want to give it. Still, here are a few tips to help you choose.

Add the Saxon genetive ‘s for specific entities

As I said earlier, the Saxon genitive ‘s personalizes the subject or object with which it is associated. In a sense, it separates it from other similar entities. So don’t hesitate to use it with boundary nouns to refer to a specific entity. For example, “the neuron’s nucleus” emphasizes that you’re talking about the nucleus of the neuron and no other cell.

Using of for clarity

The of construction is better for cases where using ‘s makes the sentence sound awkward or overly complicated or when a more formal tone is desired. For example, “The analysis of the cell’s membrane composition” is easier to understand than “the cell’s membrane’s composition analysis.”

Use the zero possessive for categories

The zero possessive is ideal for all categories, whether involving animate subjects or inanimate objects. So it’s equally suitable for nouns on the borderline between the two, such as in: “stem cells,” “gut bacteria,” “heart function,” “liver enzyme,” “Human Immunodeficiency Virus,” or “bread yeast.”

Possessives with multiple authors: The case of “et al.”

“Et al.” is an abbreviation of the Latin phrase “et alia,” which means “and others.” Academic writers use “et al.” to refer to a list of authors without naming them all.

Again, there is no hard and fast rule for how to use the possessive with “et al.” You’ll find plenty of articles using “et al.’s” (for example, in “Smith et al.’s study”), and you can choose to do the same. I don’t think a reviewer will consider these “et al.” as a reason to reject your article. But it’s generally best to avoid “et al.’s” as it quickly sounds complex and awkward. So, rather than writing “Smith et al.’s study,” I’d advise you to turn the sentence around using wording such as “Smith et al. (2015) found that…”

In Sum

If, like me, you’re feeling self-conscious about not knowing how to use possessives in English, I hope this article has shown you that there’s no need to beat yourself up because possessives in English are an absolute mess. Or let’s put it this way, in most cases, deciding to put an ‘s, of, or nothing at all is a question of taste and context. This is probably why, as far as I know, the major scientific journals such as Science, Nature, or PNAS, as well as style guides such as the APA, don’t make any recommendations regarding the use of possessives in academic articles.

That being said, I have shared with you a few general principles to stir your possessives in a way that makes your style easy and pleasant to read, namely:

• Use the Saxon genitive ‘s for people, animals and whenever you want to personalize an entity.
• Use the preposition of for objects and concepts, and whenever you need to clarify or formalize your possessive.
• Use the zero possessive, i.e., no possessive marker added, when referring to a category or when there’s a strong association between the two nouns.

Eventually, the decision to use one possessive or the other is not just a grammatical one; it’s a stylistic choice that impacts the tone and readability of your scientific writing. Good luck possessing your possessives! If you want to keep improving your style, go check our other posts on the topic.