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Verb tenses in scientific writing: Which tense should you use?

Sticky notes with past and present verb tenses in scientific writing

If you’re fluent in English, using tenses in scientific writing should come naturally to you. You shouldn’t need to flip through a grammar book, ask a freelance editor, or search online for “methods tense” or “literature review tense”.

But verb tenses may start to haunt you if you’re writing an article for a top peer-reviewed journal and you know you have to get every detail right. For example, you may wonder, What tense should be used in methodology sections? Should the introduction or literature review be written in the present tense or past tense?

In this post I’m going to answer these and other questions on verb tenses in scientific writing to make it easier for you to understand which tenses to use in a research paper.

Past or present tense in academic writing? It depends.

There’s no consensus on how authors should be using verb tenses in scientific writing. Here is a summary of the main recommendations of academic writing experts on tenses in scientific writing.

Literature review verb tense

For the literature review, most academic editors recommend using the past simple or present perfect when talking about past research.

Use the past simple to discuss what was done in the past (the authors collected, investigated, analyzed, etc.).

Use present perfect to talk about findings from previous studies that are still valid today (the author has shown, has demonstrated, etc.).

If you don’t want to use the past simple or present perfect tense in literature review sections, your other option is the present simple tense. This is the so-called literary present.

Writing the literature review in the present simple tense helps simulate an ongoing academic conversation, to which you’re contributing (“Author et al. (2021) find…, discuss…, examine… imply…”).

In summary, what tense should the introduction be written in?

  • Past simple or present perfect tense for past research
  • Present simple for general truths or for the entire literature review section

Verb tenses in the methodology and results sections

For the methodology, almost all academic writing resources agree that the past simple tense is the logical choice. You are discussing what you did (collected data, analyzed them, and derived your results)—and all of that happened in the past.

However, you may also need to use the present simple tense to refer to figures and tables.

In summary, what tense should methods be written in?

For the methodology section, use these tenses:

  • the past simple tense to explain your methods
  • the present simple tense to refer to figures or tables

What tense should a discussion be written in?

Tenses for the discussion are similar to those for the introduction:

  • past simple or present perfect tense when referring to what you did (past research)
  • present simple for general truths or for interpretations of your data

Verb tenses in the conclusion section

For the conclusion, you may need to use several tenses. Again, when referring to general truths or implications of your results, use the present simple. When referring to what you did, use the past simple or present perfect tense.

Use the simple past when discussing the research you completed and is no longer continuing. Use the present perfect when discussing an action that started in the past and is still happening now, or an action that happens regularly.

So, for the conclusion, use these tenses:

  • present simple for things that are true at the time of writing, the conclusions of your study, and its implications
  • past simple or present perfect tense for past work

Knowing how to use verb tenses in scientific writing is better than imitating other authors

In scientific writing, using verb tenses inconsistently or unnecessarily shifting tenses means sloppy writing. A poorly written manuscript submitted to a peer-reviewed journal will come back with a long list of revisions—if it’s accepted for publication. Hiring a freelance editor for research papers can help you polish your writing style and improve the likelihood that your manuscript will be accepted the second time.

If you don’t want to hire a freelance editor, you may need to edit your own research paper. Mastering verb tenses in scientific writing will help you make the right choice for each section of your paper.

Try to resist the temptation to imitate others’ writing style. It’s common for new authors to learn academic writing the same way they learned to speak: by imitation. They peruse some articles published in their target journal to see what verb tenses other authors used and then make the same choices.

However, this is not such a great idea, because not all published articles are examples of good writing. You risk imitating an author that didn’t pay much attention to verb tenses in scientific writing, or whose work was edited by someone with little experience.

How to choose the right verb tenses for a research paper

If emulating others’ writing style comes with the risk of picking up bad habits, how do you choose the right verb tense to use in a scholarly paper?

Unfortunately, style guides, academic writing books, and academic editors give conflicting advice. A solution to this problem is to follow the recommendations of your university’s writing center if you’re writing a PhD thesis or dissertation. If, however, you’re writing a research paper for a journal, follow its guidelines.

Some publishers may let you choose any style guide as long as you’re consistent. In that case, go with the style popular in your academic field (for example, APA Style in social sciences).

Example: Verb tenses in APA Style

If you need to follow the APA Style, it has precise instructions on using verb tenses in research papers:

  • Introduction and literature review: To talk about previous studies, use the past simple or present perfect; for findings that continue to be true, use the present simple.
  • Methodology and results: To talk about your methods or results, use the past simple or present perfect.
  • Conclusions: Write the conclusions of your research and implications of your findings in the present simple.

Here are some examples to help you understand how to use verb tenses in APA:

  • Past simple tense to discuss past work:

Author A (2017) showed that varied populations display similar patterns, but Author B demonstrated that patterns vary wildly

  • Present perfect to discuss findings from previous studies that are still valid today:

Other researchers have described similar processes in other environments

  • Present simple to express general truths, facts, or ideas accepted today:

Most researchers agree that our species appeared in Africa

  • Present perfect or past simple tense to describe your methods and results:

We have observed no variation in the economic growth rate, but found it depends on several factors

  • Present simple tense to describe the conclusions and implications of your study:

Our results indicate a strong correlation between A and B, but we need further research in this area

Use the right tenses in scientific writing for clarity

The goal of using the right verb tenses in scientific writing is clarity. So, whether you follow your instincts, your advisor’s suggestions, an editor’s recommendations, or a style guide, aim at clarity and logic. A well-written manuscript will have a better chance of being accepted for publication. Also, it won’t require several rounds of revision to improve its language, meaning you save time and can focus on your science.

Do you need to hire a freelance editor for a research paper? Send me a message at editor@languageediting.com.

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Last revised on 23 June 2022

Cristina N.

A freelance editor and writer with a keen interest in science, nature, and communication, I love to craft articles that help and inspire people.