“Peer review is a privilege, and an invitation to conduct such a review is a professional honor” [1]. An effective review of a manuscript is a gift for authors, editors, and the academic field [2]. Peer review is an essential part in ensuring the quality of papers published in scientific journals. Good reviews are beneficial for both authors and journal editors; authors will have the opportunity to improve their manuscripts in terms of quality, clarity, and accuracy, and editors will receive valuable comments to aid themselves to make their decisions on publication of manuscripts [3].

There have been a plethora of research articles on general guidelines for the peer review [2-6]. However, it is difficult to find papers on what kind of English expressions peer reviewers can use, in particular for non-native English-speaking reviewers. Writing poor reviews could be damaging to peer reviewers because they might not be invited to review manuscripts again and even might be evaluated as low quality reviewers in some journals [7]. Good reviews should contain not only constructive content but also appropriate English expressions so that authors and editors can clearly understand what the reviewers mean to describe. For non-native English-speaking peer reviewers, however, English writing is another substantial obstacle in providing good reviews on top of the review content itself. They need to make an extra effort to hone their English skills to write good reviews in English. Therefore, the aim of this contribution is to provide “down-to-earth” guidance for non-native English-speaking reviewers to construct better quality reviews. To this end, I, as an academic researcher and a formal English teaching professional myself, suggest useful English expressions to help peer reviewers, whose mother tongue is not English, enhance the quality of their reviews.

To begin with, let us briefly review some considerations for reviewers when deciding whether to review a manuscript suggested by an editor [2,5,8]. First of all, reviewers should assess if they have time to complete the review within the requested time frame. If they are too busy with other obligations, they should decline the opportunity and might suggest alternative reviewers. Second, reviewers should assure that they have professional expertise in the manuscript research field. If they are not familiar enough with the subject, they should not accept the review invitation. Finally, reviewers should check whether they have a conflict of interest with authors of the manuscript or the manuscript itself. If there exists some sort of relationships in reviewing the manuscript, they should turn down the invitation; otherwise, this will prevent fair, impartial, and objective reviews.

PLOS introduces a framework for organizing reviewer comments in an effective way [9]. In the first section, reviewers should provide the summary of the research and overall impression, which is regarded as the most important information. In the second section, reviewers should demonstrate evidence and examples to support their summary provided in the first section by separating the review into major and minor issues. In the last section, they can mention any additional points about the manuscript needing improvement. In the following I would like to explain more details in each part of the framework and suggest example sentences that non-native English-speaking reviewers can practically use in their reviews.

1) First section: Summary of the research and overall impression

The most important information should be included in the first section of the summary of the research and reviewers’ overall impression. Reviewers should summarize what the authors of the manuscript claim to inform. This summary will present to the editors how peer reviewers understood the manuscript and emphasize any major differences in perspectives among the reviewers. It will identify the study’s strengths and weaknesses, which would be reviewers’ “take-home message” for the editors [9]. To this end, reviewers should above all explicitly discuss what the main contribution of the study is; this can be done in a few sentences about the study topic [10]. Briefly starting with this will inform both the editors and the authors of what reviewers understood about the paper. Some useful sample sentences are as follows:

After describing the valuable contribution of the study, reviewers then should give their recommendation for acceptance, minor revision, major revision or rejection. Here, reviewers should keep in mind that they are not making the decision on acceptance or rejection of the manuscript; in fact, they are only giving advice to editors, and editors are the ones who ultimately decide whether to accept the manuscript or not [1]. They can utilize one of the following sentences for the recommendation [10]:

2) Second section: Evidence and examples

In the second section, reviewers should demonstrate evidence and examples to support their comments provided in the first section by structuring this section into major and minor issues [3]. Specifically, they should provide the reasons for their recommendation as well as detailed comments on specific areas for improvement [8]. That is, by dividing this section into major and minor issues, reviewers can describe the biggest issues first and then more specific issues systematically. In addition, numbering the comments is strongly recommended, considering that it will be very helpful for the authors to follow and respond to reviewers’ each comment; it will be especially helpful to the authors when the reviewers refer to specific lines, pages, paragraphs, sections, or table and figure numbers, because authors are able to know exactly which parts the reviewers are mentioning [8,9].

The major issues should consist of vital points to address, and reviewers should concentrate on the fundamentals of the study. For example, they can write comments on the originality of the research, the clarity of the research questions, or the suitability of the methods [3]. Some example sentences for the major issues are introduced in the following [10]:

More example sentences from anonymous reviewers are as follows:

In terms of the minor issues, reviewers should be aware that minor issues are still critical for improving the quality of the manuscript although they will not largely influence the main conclusions of the study [3]. Minor issues might be comprised of missing references, technical clarifications, data presentation, figures and tables, typos, spelling, grammar, phrasing issues and so on [10]. Some useful sentences from anonymous reviewers to describe minor issues are as follows:

3) Last section: Additional points

Finally, reviewers can leave any additional comments about the manuscript in addition to the summary of the research as well as major and minor issues. Some helpful example sentences are as follows:

4) Reviewing a revised manuscript

In addition, when reviewing the revised manuscript, reviewers can refer to the following sentences excerpted from anonymous reviewers’ comments.

In order to provide effective feedback to authors, peer reviewers should justify their recommendations with constructive comments, concrete evidence, and specific examples [3,9]. The comments should be as specific and thorough as possible so that the authors know exactly what they need to revise to improve their manuscript. Importantly, peer reviewers should always keep in mind that they should be respectful in a writing tone. This could be also difficult for non-native English-speaking reviewers, because of the foreign language issue. It is hard to use a proper tone when it comes to English writing for them. It could be helpful for them to ask native English speakers to check whether the expressions in some of their earlier reviews are polite and also reflect cultural norms. Then reviewers will be able to write their reviews more confidently in a respectful way. Peer reviewers should be also professional in their writing, and they should remember to mention what they liked about the manuscript.

On the other hand, there are some considerations that peer reviewers should not include [9]. For instance, they should not suggest additional or unnecessary experiments that might be out of scope for the research or for the journal criteria, or take an extended period. They do not have to describe exactly how the authors should revise their manuscript; peer reviewers do not need to do work for the authors; the authors will know what they have to do to revise, and that is their obligations, not the reviewers’. Reviewers should avoid promoting their own research or hypotheses to persuade authors in their reviews. Furthermore, reviewers do not have to highlight typos and grammar mistakes in writing. If the manuscript needs considerable revision in terms of language and writing quality, reviewers can just mention this in their comments. Finally, reviewers should not submit their reviews without proofreading it; it is important for them to check everything carefully one more time before the submission.

In this article I briefly introduced general guidelines and suggested specific example sentences for peer reviewing. This paper is one of the first papers that provides practical English expressions for peer reviewers, whose mother tongue is not English, to construct better quality reviews. Since most journals have specific guidelines for peer reviewers, reviewers can tailor the expressions that I introduced in this article according to the journals that they are serving. Given that reviewers also constantly get reviews of their own papers as authors, it would be advantageous for non-native English-speaking reviewers to refer to how other reviewers, especially native English-speaking reviewers (we can probably tell by their affiliations and names), write their comments. This could help them compensate for the disadvantage of being non-native English speakers.

Finally, peer reviewers are at the same time authors as well. Thus, I personally agree with the golden rule that reviewers should deal with the manuscripts they are reviewing the same way they want to get their own manuscripts treated [1,12]. Therefore, reviewers should write while bearing in mind how they would feel as authors themselves if they were to receive similar reviews of their own manuscripts from other peer reviewers. This highlights that reviewers should try not to offend the authors in any way but show respect for authors by using a polite and modest tone in their comments.

I am grateful to many anonymous reviewers whose comments were cited in this manuscript.

The author has nothing to disclose.