In scientific writing, English is a commonly used language for widely communicating important findings, meaning that a lot of non-native authors must learn the language to help their research reach global audiences. However, English grammar can be challenging to learn due to its many unique elements. The English language has borrowed significantly from other languages whilst also developing its own complex rules, meaning that it can prove difficult for non-native speakers to familiarise themselves with grammar terms.

However, it is not just non-native authors that struggle with the complexities of English grammar. Authors whose first language is English still make common mistakes. Therefore, to help all authors familiarise themselves with the English language, we have created a glossary of grammar terms to make scientific writing easier.

Word classes

Word classes are categories that showcase the grammatical functions of types of words. Most words belong to several categories, with their function depending on the context they’re being used in. Word classes in English include conjunctions, prepositions, and verbs. This is not an exhaustive list, but these are word classes that are most used in English and frequently cause issues for authors. The word classes are outlined below.

Conjunctions

Conjunctions are words used to link other words, phrases, and clauses together, enabling relations and complex things to be communicated. There are three main conjunction types: coordinating, correlative, and subordinating.

• Coordinating: These conjunctions connect words, phrases, or independent clauses of equal grammatical importance (and, but, or, for, yet, nor, so, etc).
• Correlative: These conjunctions work in pairs (i.e., either/or and neither/nor) that together provide meaning to a sentence.
• Subordinating: These conjunctions connect dependent and independent clauses within sentences, demonstrating a logical relationship between the two (because, while, that, although, etc).

Prepositions

Prepositions are elements of a sentence that demonstrate relations between words. They provide information about place, time, and direction or movement, which is why they are crucial for authors aiming to accurately report on scientific findings. Here are some examples of prepositions in a scientific context.

• The samples were stored in a sub-zero storage container.
• Patients were checked two hours after
• The solution was poured onto the testing strip.

Verbs

Verbs are used to show that the subject of a sentence is doing something (action), experiencing or feeling something (state of being), or that something is happening (occurrence). They generally connect the subject of a sentence to an object. Common verbs include be, have, and see.

Verbs are important in scientific writing because they describe the actions that were taken during a study and any occurrences observed. Scientific writing usually reflects on past studies, meaning verbs tend to be used in their past tense forms.

• Participants showed signs of an allergic response almost immediately.

Auxiliary or modal verbs are verbs that demonstrate possibility, ability, permission, or necessity. They help form the tenses and moods of other verbs, providing supplementary or additional information to a sentence and its action. Modal verbs are an important part of scientific writing, so authors should familiarise themselves with them.

Punctuation

Punctuation is a set of symbols used to structure language, separate or connect ideas, and clarify meaning. Its role is to mimic pauses and intonations in speech, making text easier to read and understand. Common examples of punctuation include commas, semicolons, dashes, hyphens, and full stops. Again, this is not an exhaustive list; instead, it addresses commonly used (and frequently misused) types of punctuation in scientific papers.

Commas

Commas are grammatical symbols with a variety of functions. Main functions of commas include making meaning clear by separating parts of a sentence, constructing lists, and indicating introductory phrases.

Commas are commonly used to separate independent clauses, which are then joined by a coordinating conjunction.

• The results were inconclusive, but the data remain useful for future studies.

Lists are commonly used in scientific papers, especially in the methods section, where items and substances used during the study may be identified.

• The following solution types were used in the first experiment: liquid in liquid, liquid in solid, solid in gas, and solid in liquid.

Dashes

There are two kinds of dashes: en dashes (–) and em dashes (—).

En dashes are used to connect ranges of numbers, dates, and time, and they literally mean “through”.

• Pages 12–18 describe the methodology used during the study.
• We checked the samples in September–November.

Em dashes function like commas or colons but indicate a much stronger break, often for emphasis or to clarify meaning.

• The study was humane—no animals were tested on.

Hyphens

Hyphens are used to join words together to create compounds that clarify meaning.

• We moved the room-temperature solutions to a stable environment.

They are not generally considered a type of dash, although they do look like one, thus causing confusion for authors. Read our article on dashes and hyphens to ensure you are using each correctly.

Semicolons

Semicolons are used to connect two closely related independent clauses. These clauses are a continuation of an idea, and not two separate ones.

• Tree sap was present at the site; we collected samples using spiles.

A semicolon instead of a comma is used in the above example because both parts are complete independent clauses. Incorrect use of a comma here is termed a comma splice.

Semicolons can also be used for lists. Whereas commas are employed for standard lists, semicolons are used for more complicated lists where additional information is given, but the connection between elements in the sentence is unclear.

• The following samples were analysed: 100 mg of oak bark, dried; 50 mg of garlic bulb, washed and peeled; and 25 mg of powdered root.

Here, the use of commas would only cause confusion. The semicolons function to ensure that each item in the list correctly corresponds to its specified weight and condition. Semicolons and commas are often confused, so make sure you learn the correct usage of each.

Improving your English grammar

Improving your English grammar is something that takes time and effort. Ensuring you are familiar with common and frequently misused grammar terms is the first step to writing a grammatically sound scientific paper. If you need help with English grammar, hiring a professional editor is a good way to ensure your paper is ready for publication.

At MDPI Author Services, we specialise in helping researchers prepare their manuscripts for publication. Our Figure Editing Service provides publication-ready figures that clearly communicate your research to readers. Figure editing enhances your charts and graphs by revising the colours, shading, size, resolution, borders, font, and file type. This is all completed in one business day after payment. Click here for a free quote.

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