Verb tenses are useful for providing readers with context about actions and events, more specifically about when in time they happened. Scientific writing relies heavily on describing past actions and events, though it sometimes requires other uses of verb tenses, so it’s important that authors understand what verb tenses are before writing a research paper.

An important part of constructing a well-written scientific research paper is consistently using the correct verb tenses. Here, we show you when, where, and how to use different verb tenses.

What are verb tenses?

Verb tenses are used to show when something – an action, state of being, or occurrence – is taking place. The English language has three tenses which are used to modify verbs: past, present, and future. When writing, the verb tense you use demonstrates to readers if something has already happened, is happening now, or will happen in the future.

For each of the three main verb tenses, there are also four aspects that add extra information: simple tense, perfect tense, continuous tense, and perfect continuous tense.

The table below shows how the tenses are modified by each different aspect.

	Past	Present	Future
Simple	We conducted the study one month ago.	We conduct the study every month.	We will conduct the study next month.
Perfect	We conducted the study before analysing the samples.	We have conducted the study many times over the years.	We should have completed four studies in total by this time next year.
Continuous	We were conducting the study when participant one dropped out.	We are conducting the study today.	We will be checking the study samples every Monday over a twelve-month period.
Perfect continuous	We had been conducting the study until participant one dropped out.	We have been conducting the study all day.	We will have been checking the samples for three months by March.

With twelve unique verb tenses in total, it can be hard to memorise the specifics of each. Instead, we outline the verb tenses you will most likely require in scientific writing.

Verb tenses in scientific writing

According to the George Mason University Writing Centre, only three verb tenses make up 98% of all verb tenses used in academic writing. These are the simple past tense, simple present tense, and perfect present tense.

Scientific writing is a type of academic writing, and these three verb tenses are all common in science papers. Simple future tense is also a popular verb tense in scientific writing. For example, when discussing if the study or findings will require further follow up in future.

Scientific research papers are typically divided into sections, each one trying to convey certain information to the reader. These different sections of a scientific research paper have different purposes. And this means they will require the usage of different verb tenses where appropriate.

How to use verb tenses in a scientific research paper

Taking the most popular verb tenses in academic writing as a starting point, we explain which sections of a scientific research paper you may use them in.

Abstract and introduction

Abstracts and introductions function to frame research papers, outlining the rationale and scope based on what is already known (or not known) within a field and what the hypothesis seeks to address. Abstracts summarise information that you’ll expand upon in your introduction, in addition to providing overviews of methods and results and insights into any findings.

For these reasons, the introductions and abstracts of scientific papers tend to look to the past for context, the present for what is known now, and the future for what may be possible to know. Therefore, they often use the simple past tense, simple present tense, simple future tense, and perfect present tense.

For example, the simple past tense:

• Christensen et al. first documented the presence of this chemical in their seminal paper.

Simple present tense:

• This study is the first of its kind.

Simple future tense:

• We hope that this study will provide a breakthrough in the understanding of molecular chemistry.

Perfect present tense:

• Past research has shown that alkaline water has a negative impact on the growth of sphagnum moss.

Methods and results

The methods section of a paper describes the procedures carried out during a study. These events were in the past, so the simple past tense is appropriate here:

• The pipettes were cleaned before the second round of testing.

A lot of scientific writing uses the passive voice, like in the example above. However, it is generally recommended to use active voice where possible. This means giving emphasis to the person performing the action of the sentence, rather than the person or object being acted upon:

• We cleaned the pipettes before the second round of testing.

Because the results section describes the results of the study found in the past, the simple past tense is also appropriate here:

• We observed that there were significant statistical anomalies between the two data sets.

Conclusion/discussion

Conclusions or discussions function to summarise results, reflect on the importance of any findings, and discuss future implications. Therefore, like abstracts and introductions, they often use a combination of the simple past tense, simple present tense, simple future tense, and perfect present tense.

For example, the simple past tense:

• We detected no statistical anomalies after the third round of testing.

Simple present tense:

• These findings are consistent with previous data.

Simple future tense:

• These findings, we hope, will benefit the wider scientific community.

Perfect present tense:

• We are confident that our research has shown the impact of temperature on solution quality.

Resources on verb types

As well as verb tenses, types of verbs such as modal verbs can cause further confusion for authors. Check out our guide on how to use model verbs in scientific writing to ensure that you understand how verbs work with grammatical modifiers as well as tenses.

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