The perfect
The perfect is not a tense, it is an aspect.You combine the perfect with a tense (past, present, or future) to add detail about how the activity happened. For example, you can suggest that an activity isn't finished yet (present perfect).
Present perfect
Since 1950, the population has grown exponentially.
This sentence says that something (the population growing very fast) started in 1950, but it doesn't say when the activity ends. It hints that the activity continues up to the reference time - which is right now, when we are speaking - and it may keep happening for a long time afterwards, too.
We are talking about a past activity, but our focus is on right now.Why do we do this? Often, we do this to hint that there is some connection between the past activity and now. For example:
Global CO2 levels have increased since 1960. [This implies ' ... and now there is some effect from this'.]
From 1750 to 1950 the population increased by only 2 billion. Since 1950 it has
grown much faster. [This implies '... and we can see a result now'.]
We also use the present perfect to talk about a time period that hasn't finished yet, such as this decade or this century. For example:
There were around 80 major earthquakes in the twentieth century, and there
have been 14 major earthquakes this century. [This century= from 2000 to 2099.]
Although Comptronic started selling mobile phones after its rivals, it has earned
around $5 billion this decade, and is expected to become the number-one company
in the next decade. [This decade= from 2010 to 2019, next decade= 2020-29.]
Future perfect
The graph shows that by 2050, the world population will have grown to 10 billion people.
With the future perfect, the focus is on a reference time in the future (2050), but you also hint about things happening before and after this time.
An activity (growing) started at some time before 2050. The activity is still happening in 2050. The future perfect suggests that the activity could continue after 2050.
In other words, the future perfect is used to focus on an interesting point in a story. This point is usually near the end of the story and a lot of interesting things have happened in the story before this interesting point.
Activity 5.5
Predict the future based on the information. Use the key words to write your sentence. The first one has been done for you.
- News websites are becoming more and more popular, while print newspapers
are becoming less popular. By 2030/ print newspapers/ disappear/ and/ news
websites/ replace/ them.
Answer: By 2030, print newspapers will have disappeared and news websites
will have replaced them.
- Around 6000 square kilometres of the Amazon rainforest are destroyed every year.
Within 40 years/ the Amazon rainforest/ disappear.
Answer
Within 40 years, the Amazon rainforest will have disappeared.
- Startup.com competes aggressively with a rival company, Dinosaur.com. In ten
years/ Startup.com/ crush/ Dinosaur.com.
Answer
In 10 years, Startup.com will have crushed Dinosaur.com.
- A company is selling its assets and not creating new ones. In five years· time/ the company/ sell/ all its assets/ and/ it/ go bankrupt.
Answer
In 5 years' time, the company will have sold all its assets and gone bankrupt.
- These days, Japanese car manufacturers tend to make their cars offshore (in
other, cheaper countries}. This trend will continue. By 2040 / all Japanese car
manufacturers/ move/ offshore/ and/ all the car factories in Japan/ close.
Answer
By 2040, all Japanese car manufacturers will have moved offshore and all the car
factories in Japan will have closed.
- Country A has more oil reserves than country B, but it uses them faster. They will not last for a long time. By 2053/ Country A's oil reserves/ run out.
Answer
By 2053 country A's oil reserves will have run out.
Past perfect
CO2 levels had risen significantly before there was an increase in global
temperatures.
By 1970, exports had increased to 15 million cars per year.
You don't use the past perfect by itself.You must always use the past perfect with another past tense, or with a date in the past. It is used to show the sequence of events in the past.
The past perfect is a skilful way to show the order of events, without using words like 'first', 'second', 'next', 'then'. Let's try an example.
Activity 5.6
Use this information to complete the sentences on the next page, using the words given. The first one has been done for you.
- The injury rate/be steady at around 20 per year/when the company/introduce/
new machines.
Answer: The injury rate had been steady at around 20 per year when the company introduced new machines.
- The company/appoint/ a safety manager/after the injury rate/triple.
Answer
A safety manager was appointed after the injury rate had tripled.
- By 1992, the injury rate/not/decrease.
Answer
By 1992, the injury rate had not decreased.
- Although the safety classes/halve/the injury rate, they were replaced with a
safety manual in 1995.
Answer
Although the safety classes had halved the injury rate, they were replaced by a safety manual in 1995.
- It seems the safety classes/were/very successful. However in 1993 the injury rate /be/still higher than it/be/in 1988-89, before introducing the new machines.
Answer
It seems the safety classes were very successful. However, in 1993 the injury rate was still higher than it had been in 1998-99 before introducing the new machines.
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