句型

General Function 11. Writing about the past

2022-03-28 07:51:12 simyang 3

Writing about the past

Writing about the past in English is made difficult by the rather complex tense system. However, the phrases grouped below give an indication of the uses of the main tenses in academic writing. For a comprehensive explanation of the uses of the various tenses you will need to consult a good English grammar book. A good recommendation is Practical English Usage by Michael Swan, Oxford University Press.

Time phrases associated with the use of the simple past tense: specific times or periods of time in the past
During the Nazi period,
Between 1933 and 1945,
From 1933 to 1945,
In the 1930s and 1940s,
restrictions were placed on German academics.
For centuries,
In the second half of the 19th century,
At the end of the nineteenth century,
church authorities placed restrictions on academics.
Following World War I,
In 1999,
Fleming actively searched for anti-bacterial agents.
Fleming was named one of the 100 Most Important People of the century.
Time phrases associated with the use of the present perfect tense: past and present connected

To date, little evidence has been found associating X with Y.
Up to now, the research has tended to focus on X rather than on Y.
So far, three factors have been identified as being potentially important: X, Y, and Z.
Since 1965, these four economies have doubled their share of world production and trade.

Until recently, there has been little interest in X.
Recently, these questions have been addressed by researchers in many fields.
In recent years, researchers have investigated a variety of approaches to X but …
More recently, literature has emerged that offers contradictory findings about …

The past decade has seen the rapid development of X in many …
Over the past 30 years there has been a significant increase in …
Over the past century there has been a dramatic increase in …
Over the past few decades, the world has seen the stunning transformation of X, Y and Z.

The present perfect tense may also be used to describe research or scholarly activity that has taken place recently

Several studies have revealed that …
Previous studies of X have not dealt with …
A considerable amount of literature has been published on X.
There have been several investigations into the causes of illiteracy (Smith, 1985; Jones, 1987).
The new material has been shown to enhance cooling properties (Smith, 1985, Jones, 1987).
Invasive plants have been identified as major contributing factors for the decline of …
The relationship between a diet high in fats and poor health has been widely investigated (Smith, 1985, Jones, …

For reference to single investigations or publications in the past, the simple past tense is used

An experimental demonstration of this effect was first carried out by …
The first experimental realisation of …, by Smith et al. [12], used a …
The first systematic study of X was reported by Patel et al. in 1986.
Smith and Jones (1994) were the first to describe X, and reported that …
X as originally isolated from Y in a soil sample from … (Wang et al., 1952).

In 1975, Smith et al. published a paper in which they described …
In the 1950s, Gunnar Myrdal pointed to some of the ways in which …
In 1981, Smith and co-workers demonstrated that X induced in vitro resistance to …
In 1984, Jones et al. made several amino acid esters of X and evaluated them as …
In 1990, Patel et al. demonstrated that replacement of H2O with heavy water led to …
Thirty years later, Smith (1974) reported three cases of Candida Albicans which …


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