Verb Tenses in the Methods of the Article
In the methods section, we describe what has happened during the study. So it is better to use the simple past tense for verbs.
“We tested independently derived cultures for resistance to trimethoprim.”
“Cells were transfected, irradiated, and assayed for DNA damage.”
When one action occurs before another, we use the past perfect tense for the former action and the simple past for the latter.
“The cells that had been irradiated [Past Perfect] were assayed Simple Past] for DNA damage” and “Patients who had elected [Past Perfect] to undergo surgery completed [Simple Past] questionnaires.”
Sometimes, when one action occurs at the same time as another one, it is better to use the past continuous:
“while the cells were incubating [Past Continuous], the temperature was raised [Simple Past] 1°C per hour” or “while patients were preparing [Past Continuous] for surgery, nurses collected [Simple Past] baseline samples”
Verb Tenses in the Results of the Article
The researcher has carried out experiments and tests when the article was not yet completed. The results have also been obtained in the past. So for the results section, we mainly use the past tense.
“We detected no fluorescence in the control sample.”
“All participants reported a significant reduction in pain.”
In certain cases, it is better to use the simple present. As we explained earlier in the part on introduction, when referring to the whole article or a detail of the article (figures, tables, different sections of the article, results, or data), we can use the simple present.
“Our results demonstrate that magnesium is essential for enzymatic function.”
“Figure 1 shows our fluorescence data.”
“In this study, we report the discovery of a new species of frog.”
Remember that sometimes we can use two different tenses in a single sentence:
“Because no enzymatic activity was detected [Simple Past] in the absence of magnesium, our results indicate [Simple Present] that magnesium is [Simple Present] absolutely required.”
In the above sentence, the tense of the last verb is a simple present. It is because the author believes that the conclusion is a general rule.
Verb Tenses in the Discussion of the Article
The “Discussion” section follows the same rule as the other sections of the article. If you are referring to specific results or methods, use the simple past. If you are presenting the result of the article, use simple present:
“We conclude that gene X is dispensable for ornithine synthesis.”
But, the discussion may also include future tense. If you are making suggestions for future studies, you can use the future tense:
“the methods reported here will allow for rapid screening in the field”
“we will publish the full results of our screen as part of another study.”