Mastering Verb Tenses in Literature Reviews

Nurse Author & Editor, Winter 2004 by Johnson, Suzanne Hall

Deciding on which verb tense to use when writing the literature review section of a manuscript is challenging. Editors find that verb tense problems are common in literature report sections of manuscripts. Authors, reviewers, and editors need to be able to spot incorrect verb tenses in literature reviews. Try editing verb tenses in the sample enclosed in this article and compare your work with that of a nursing journal editor.

Verb tenses convey the timing of events. They help readers understand if something occurred in the past, present, or future. Therefore, verb tenses help readers place information within a sequence of events. However, unnecessary changes in verb tenses interrupt the flow of the material and make reading more difficult.

From my past experience editing Dimensions of Critical Care Nursing, many nurse authors have difficulty with verb tenses in the literature review or conceptual framework sections of their manuscripts. Sometimes, they seem to have used tenses without regard to the timing of the events. Other times, they have switched tenses without purpose within paragraphs or even sentences.

When you describe something that occurred at a specific time in the past, followed by a different statement regarding the current situation, you should switch from past to present tense. However, some authors switch tenses even when they are consistently describing information from published literature.

These problems can be corrected easily by applying a few principles. These principles will help the nurse author to decide which tense is appropriate and the nurse reviewer or editor to correct submitted manuscripts.

Past Tense

Past tense should be used when you describe something that occurred at a very specific time in the past. Within the literature review section of a manuscript this usually applies to descriptions from:

* Research reports, because they were completed at a specific time in the past.

* Published articles and books, because this information was published before the current manuscript was written.

* Statements by authorities, because the statements were made in the past.

Examples of the correct use of past tense in sentences from literature reviews include:

* Investigators found that . . . .

* The researchers studied four factors.

* The subjects were between the ages of . . . .

* The data were analyzed using . . . .

* The author wrote about . . . .

* Jones described four factors . . . .

Notice that the above examples all describe some aspect of a study or publication that was completed at a certain time in the past. Therefore, past tense is the best verb tense for these sentences and it should be the primary tense for the literature review and results sections of most manuscripts.

Past Perfect Tense

In the literature review section, you might want to describe one specific study that was finished before another. Both were completed in the past, however the order of completion was significant. In this case, emphasize the difference in timing by using the past perfect tense. Showing the timing and relationship of studies is critical to building the theoretical basis for the study or project.

Interestingly, this grammar guideline has been recommended for many years, yet many authors still do not use the past perfect tense when it is appropriate. In fact, as early as 1978, the Council of Biology Editors Style Manual had described the use of the past perfect tense: "The past perfect tense is used to describe events completed before a time in the past. . ." (p. 21). This organization, now called the Council of Science Editors, is preparing a new manual that will be released in 2004, which will likely emphasize correct verb tense again.

The past perfect tense is often constructed by using the word "had" or "have" before the verb (Darling, 2003). Sentences that might appear in a literature review section using the past perfect tense are:

* The investigator had completed the assessment tool study before she started the controlled research one.

* The human rights committee had approved the project before the subjects were selected.

* Jones had found the factor before Jeffrey started his project.

* The patients in this study had already completed three patient education classes at the time this study was started.

Present Perfect

Confusion also occurs among some nurse authors regarding when to use the present perfect tense. The present perfect tense denotes something that occurred at an undetermined time in the past or that continues today. For example, this tense might be used in literature reviews when you want to describe what an investigator suggests for current (continuing) practice based on her or his study.

The Publication Manual of the American Psychological Association (2001) described this clearly when the authors wrote: "Use the present perfect tense to express a past action or condition that did not occur at a specific, definite time or an action beginning in the past and continuing to the present" (p. 43).

Examples of present perfect tense conveying that something was completed at a uncertain time in the past are: