Most scientists I know are fluent in English, even if they are non-native speakers. However, as the saying goes, “the devil is in the detail.” And the best of us can make subtle mistakes, substituting one word for another.

In this post, we delve into five common mistakes that often sneak into scientific articles. And you’ll have the opportunity to put your mastery of Shakespeare’s language to the test with a short quiz for each type of mistake.

1. Assume vs. Presume

Quiz: Which sentence is correct?

• a) “Until further data is available, we will assume that the treatment has no side effects.”
• b) “Until further data is available, we will presume that the treatment has no side effects.”

‘Assume’ is used when the outcome is uncertain. ‘Assume’ is often used when making a hypothesis or simplification that is not necessarily backed by strong evidence. For instance, you would write: “To simplify the model, we assume that all variables are independent.”

‘Presume’ is used when there’s a degree of certainty based on supporting evidence. ‘Presume’ is used when making a statement that is expected to be true based on existing evidence or general consensus. For instance, you would write: “Since the model has been thoroughly tested in previous studies, we presume it to be accurate for our experimental conditions.”

Now, what do you think is the correct response to the quiz? (You’ll find the correct response at the end of the post).

2. Compliment vs. Complement

Quiz: Which sentence is correct?

• a) “The findings compliment the theory perfectly.”
• b) “The findings complement the theory perfectly.”

‘Compliment’ refers to expressing praise. For instance, you would write: “The reviewer complimented the rigor and depth of our experimental design.”

‘Complement’ means to complete or enhance something. For instance, you would write: “The recent findings complement our current understanding of the phenomenon.”

Now, what do you think is the correct response to the quiz? (You’ll find the correct response at the end of the post).

3. Principle vs. Principal

Quiz: Which sentence is correct?

• a) “We based our hypothesis on the principle of natural selection.”
• b) “We based our hypothesis on the principal of natural selection.”

‘Principle’ refers to a basic truth or law. For instance, you would write: “The conservation of energy is a fundamental principle in physics.”

‘Principal’ means the most important item or a person in a position of authority. For instance, you would write: “Our principal concern was ensuring the accuracy of the data.”

Now, what do you think is the correct response to the quiz? (You’ll find the correct response at the end of the post).

4. Infer vs. Imply

Quiz: Which sentence is correct?

• a) “The patterns in the data imply a possible relation between the two variables.”
• b) “The patterns in the data infer a possible relation between the two variables.”

‘Infer’ means to deduce. ‘Infer’ is generally used when drawing a conclusion based on evidence or reasoning. For instance, you would write: “From the experimental data, we can infer that the treatment had a significant effect.”

‘Imply’ means to suggest indirectly. ‘Imply’ is used when indicating something without explicitly stating it. For instance, you would write: “The inconsistencies in the experimental results imply the potential presence of uncontrolled variables.”

Now, what do you think is the correct response to the quiz? (You’ll find the correct response at the end of the post.)

5. Discrete vs. Discreet

Quiz: Which sentence is correct?

• a) “The experiment has three discreet stages.”
• b) “The experiment has three discrete stages.”

‘Discrete’ means separate or distinct. For instance, you would write: “The data set can be broken down into several discrete categories.”

‘Discreet’ means careful or unobtrusive, often in a sensitive context. For instance, you would write: “Be discreet when discussing the confidential aspects of the research.”

Now, what do you think is the correct response to the quiz? (You’ll find the correct response at the end of the post.)

The solutions!

Accurate word choice is more than semantics—it’s the cornerstone of clear, effective scientific communication. In this post, we looked at five common mistakes scientists make when writing in English, especially non-native speakers. How did you do in this quiz?

To find out if your hunch was right, check out the correct answers below.

Quiz 1: Assume vs. Presume

• a) “Until further data is available, we will assume that the treatment has no side effects.”
• b) “Until further data is available, we will presume that the treatment has no side effects.”

The correct sentence is a. One uses the verb ‘assume’ when a proposition is accepted as true for the sake of argument or investigation, without necessarily having substantial proof (i.e., here “Until further evidence is available). ‘Presume’ supposes that the proposition is likely true based on probability or reasonable evidence.

Quiz 2: Compliment vs. Complement

• a) “The findings compliment the theory perfectly.”
• b) “The findings complement the theory perfectly.”

The correct sentence is b. ‘Complement’ is generally used in the context of one thing enhancing or completing another (such as “the findings” completing “the theory”), while ‘compliment’ typically refers to a remark expressing approval, admiration, or respect.

Quiz 3: Principle vs. Principal

• a) “We based our hypothesis on the principle of natural selection.”
• b) “We based our hypothesis on the principal of natural selection.”

The correct sentence is a. Remember, ‘principle’ generally refers to a basic concept or law (such as natural selection), while ‘principal’ indicates something or someone of primary importance or in a leading position.

Quiz 4: Infer vs. Imply

• a) “The patterns in the data imply a possible relation between the two variables.”
• b) “The patterns in the data infer a possible relation between the two variables.”

The correct sentence is a. ‘Imply’ is used when the speaker or writer suggests or indicates something without stating it outright. So, in this case, the patterns in the data are suggesting (implying) a possible relationship. ‘Infer’ is used when the listener or reader makes a conclusion based on the information presented. If a person looks at the patterns in the data and concludes there’s a possible relationship, they are inferring. Thus, data or patterns can ‘imply’, and a person (or perhaps a reasoning machine) can ‘infer.’

Quiz 5: Discrete vs. Discreet

• a) “The experiment has three discreet stages.”
• b) “The experiment has three discrete stages.”

The correct sentence is b. The term ‘discrete’ means separate or distinct, which fits the context in this case – the experiment has three distinct stages. Conversely, ‘discreet’ means careful and circumspect, often in a way that attempts to avoid causing offense or attracting attention.

Eager to continue improving your English? Check out this other post about “5 mistakes non-native speakers make when they write in English“.