Using past and present tenses in research writing
Albeit English uses an elaborate system of tenses, plain past and ordinary present are the most common tenses in research papers, supplemented by present ideal and past ideal. The word ‘perfect’ in this case means ‘made complete’ or ‘completely done,’ and ‘perfect’ tenses are used in describing two events and specifying how the two are related with respect to time.
A typical research paper goes after the IMRaD format, and how frequently a given tense is used varies with the section of the paper: the introduction, for example, uses a mix of the present tense and the past tense whereas the past tense predominates the results section. Here is a brief guide to using the four variants, namely ordinary past, plain present, present ideal, and past ideal.
Elementary past: Use plain past to describe specific deeds or events that occurred in the past and that are not being linked to the present in the same sentence. Here are some sentences in ordinary past. ‘We selected Five plants at random.’ ‘Tanaka reported that 1000 grains of wheat weighed 40 grams.’ ‘Watson and Crick published their landmark paper on the structure of DNA in 1953.’
Ordinary present: Use elementary present for stating what is generally true and unlikely to switch, as in ‘The sun rises in the east,’ ‘Human babies generally begin speaking when they are two years old’, and ‘In July and August, it rains in most parts of India.’ Use ordinary present also to indicate research results that you believe to be true and relevant to your present research, as in ‘Robinson maintains that soaking seeds in strong acids help in cracking seed dormancy.’ Lastly, plain present is used when talking about the research paper that you are writing, as in ‘Section Two.Three discusses the advantages of soaking seeds before sowing them.’
Present flawless: Use present ideal to talk about a past event that is linked to the present, to talk about trends, or about events that have ended or occurred recently or still continuing, as in ‘The use of cell phones or mobile phones to access the Internet has enlargened recently’ and ‘Multi-megawatt turbines have been used in Europe for offshore sites.’
Past flawless: Use past ideal to describe two related past events that occurred at different times in the past, as in ‘By the time they were sown, the seeds had already germinated’ and ‘Those candidates that had been exposed to radiation earlier were excluded.’
To enhance your skill about writing research papers, you could refer to the following articles:
Getting the tenses right: Materials and methods section
Is it acceptable to use very first person pronouns in scientific writing?