English predicate verb tenses are 16 * *, and there are three tenses that are frequently used in English scientific papers: simple present tense, simple past tense and future tense. The correct use of verb tenses is the basic skill of scientific research writing. When writing an English paper, if we can't choose the tense correctly, we will often change the meaning of the article, thus affecting the understanding of experts and readers.

A typical scientific paper has a basic frame structure: abstract (summarizing the background of scientific research and putting forward research questions and hypotheses), materials and methods (describing one's own research methods), results (analyzing research results) and discussion (discussing the significance of research results in depth and briefly pointing out the future research direction). According to the framework of this paper, some regular problems are discussed, hoping to help everyone.

First of all, we should grasp the following three basic points:

1, simple present tense: it is mainly used to describe the objective facts that are not limited by time, or to describe the feelings, States and relationships that occurred or existed when writing a paper, or to express gratitude. It is worth noting that out of respect, all published research results of others are generally quoted in the simple present tense as "previously established knowledge".

2. General past tense: used to describe the writer's own work in the paper. For example, describe your own materials, methods and results.

3. General future tense: used for the behavior or state of existence after writing a paper. For example, put forward the next research direction.

Abstract:

We usually use the past tense to reflect our own research results.

Introduction:

(1) The research background in the overview usually refers to the widely accepted principles or facts in related disciplines and the importance of your research, usually using the present tense.

For example, genomics provides cruel information for rational drug design.

(2) In the summary, you can also quote some research results related to your project. To express that you still believe in the correctness and relevance of the research results, you can use the present tense even if it was a long time ago.

For example, many lakes and wetlands in this area are located in craters or valleys blocked by early Pliocene lava flows (ollier &; Joyce, 1964).

Garcia (1993) pointed out that under certain conditions, individuals' income from deposits is the same as that from purchasing government bonds, so the changes in the amount of bank loans and deposits caused by changes in the amount of reserves will eventually affect the price of bonds.

It should be noted that if some outdated or invalid scientific research achievements are cited, the verbs should be in the past tense.

For example, physicists in the19th century thought that women suffered from migraine because they were the "weak sex", but current research shows that the cause of migraine has nothing to do with gender.

(Note the transition from the past tense to the present tense here)

Materials and methods:

The simple past tense is usually used to describe what you have done before writing your paper.

For example: (example 1) Total phosphorus (TP) and total nitrogen (TN) are measured in the laboratory using standard procedures.

(Example 2) A culture medium was prepared from a stock solution according to a standard protocol.

Results:

I use the past tense to explain my own research results.

For example: (example 1) Overall, more than 70% of the inserts are non-plant.

(Example 2) After continuous activation of ntooo cells, the cell cycle in both groups recovered.

The present tense is usually used to describe the contents of a chart.

For example, (Example 1) Figure 1 shows the morphological differences of donor chronicity in oocytes of two age groups.

(Example 2) The following table 1 shows the flow rate calculated for each flow using the equation 1.

Figure 1 and table 1 indicate the state of the paper at the time of writing, so the present tense is used.

Discussion:

Use the present tense to express the significance of the research results.

For example, removing vegetation for agricultural purposes seems to have a negative impact on the water quality of rivers.

Summarize the research results in the past tense and discuss and explain the research results in the present tense.

For example: (example 1) Body weight increases with the increase of feed nutritional value. The results showed that the feed with nutritional value was helpful for livestock to gain more weight.

Note that the experimental findings here are described in the past tense, while the significance of discussing this discovery is in the present tense. )

(Example 2) There is no difference in the contents of carbon and phenols in leaves at different locations, indicating a response.

Secondary phytochemicals from phenols to water are complex.

The description of this sentence has almost no hypothetical meaning, which shows that the author firmly believes in the correctness and relevance of his research results and conclusions.

Conclusion (conclusion):

The past tense can be used to emphasize the past research results, and the present tense or future tense can be used to indicate the future research direction or prospect.

For example, although the study found evidence of farming in the study area, from the collected data, it is impossible to determine whether the influence of upstream agriculture led to the increase of total nitrogen level in the downstream. Therefore, further research is needed to determine the impact of agriculture on the health of Stringybark Creek.