Past simple & present perfect
Work in pairs.
Imagine that you are at home. What common electrical appliances do you normally use?
Ask and answer questions about your home appliances.
Example: Student A: Do you use an electric kettle at home?
Student B: Oh no! I think it’s an energy-consuming device and I’m money- conscious.
A: But an electric kettle is a time –saving device, isn’t it?
B: Yes, it is.
A: And, as you know, time is money.
Make use of the phrases below.
It’s a useless thing…, an innovative staff…, it’s a waste of money…, it is time (energy, money) consuming,
I’m environment (fashion, comfort)-conscious, I’m stripped to read the manual…, it is not reliable.
6 Read the article about the history of electricity. Which of the following facts are not mentioned?
a) origin of the word electricity b) electricity is a natural phenomenon c) attractive effect of amber
d) electrical shock as a cure e) Maxwell’s equations f) positive and negative charges
Electricity is a force of nature and has been around us since the creation of universe.
Since ancient times, people have come across various instances of electricity being manifested in nature.
The earliest mention of electric phenomena is found in ancient Egyptian texts from about 2750 BC
(roughly 4750 years ago). These texts talk about electric fish that were known as ‘Thunders of the Nile’
and defenders of other fish. So the earliest discovery of electricity in recorded history was in the form of
bio-electricity!
The mention of this electric fish like catfish has been found in Greek, Roman and Arabic chronicles.
In fact in some instances, there is even a mention of electrical shocks from these fish being used as a cure
for headaches.
Many ancient civilizations have reported the attractive effect that amber has on light objects like feathers
when rubbed against cat fur. The magnetic effect of minerals like magnetite was known to the ancient Greeks.
Around 600 BC, a Greek philosopher Thales of Miletus, investigated the static electric effect of amber and
wrongly classified it as a magnetic effect arising out of friction. However, later in modern times, electricity
and magnetism were proved to be the two manifestations of a single force of electromagnetism.
After that, in 1600 AD, an Englishman named William Gilbert studiedthephenomena of electricity and
magnetism and distinguished between the electric effect of amber and magnetic effect of lodestone.
He gave the name ‘electricus’ (Latin) to the phenomenon of attraction showed by amber. Not surprisingly,
it was derived from the ancient Greek word for amber, which was ‘eleckron’. This gave rise to the modern
word of electricity which first appeared in print in the book Pseudodoxia Epidemica written by Sir Thomas
Brown in 1646.
In the 18th century, Benjamin Franklin used the Leyden jar to establish that lightning is simply an electrical
discharge, Charles Coulomb demonstrated that the force between charges is inversely related to the square
of the distance between the charges, Luigi Galvani performed experiments revealing that electricity is present
in every animal, and Alessandro Volta developed the forerunner of the electric battery.
Later, in the 19th century, Georg Ohm introduced an important relationship between potential, current, and
resistance which we now refer to as Ohm’s law, Michael Faraday demonstrated his theory of electromagnetic
induction, James Maxwell developed the electromagnetic theory of light, which among other things , revealed
that electromagnetic waves travel through air at the velocity of light.
By the end of the 1800s, a significant number of the fundamental equations, laws, and relationships had been
established, a various fields of study, including electronics, power generation, and calculating equipment,
started to develop in earnest.
Thus we see that the history of electricity runs right from the period before Christ up to the computer age
today. We owe to a certain extent, our ‘electrical lives’ to those who discovered electricity. Thanks to them,
the lightning of the skies was put to good use on Earth, in the form of this brilliant energy we can’t imagine
living without – electricity.
7 Read the article again. Are the statements true (T), false (F) or is the information not given (NG)?
1Electricity was invented by a Greek philosopher Thales of Miletus. T/F/NG
2The phenomenon of static electricity has been toyed with since antiquity. T/F/NG
3The Greeks called amber so often used to demonstrate the effects of static electricity elektron. T/F/NG
4The word electricity first appeared in print in the 17th century. T/F/NG
5 Benjamin Franklin described his famous kite experiment on June 15, 1752. T/F/NG
6 Failures never discouraged Faraday. He felt failures also teach. T/F/NG
7 Maxwell revealed that electromagnetic waves travel trough air at the velocity of light. T/F/NG
8 In 1895 Wilhelm Rontgen discovered electromagnetic waves of high frequency T/F/NG
8 Did Edison invent the light bulb, Marconi the radio, Bell the telephone, Morse the telegraph?
The answers are “no”. They didn’t invent the wheel. They were instrumental in making it better
and in some cases, obtaining the patent.
Watch the video “The Discovery Of Electricity ” and you will discover it took several people,
along the way, to make the light bulb glow.
Useful notes:
Joseph Swan – a British physicist and chemist. He is most famous for his role in the development
of the first incandescent light bulb (лампа накаливания)
spark – искра, искровой разряд
kite – воздушный змей
pots with sheets of copper inside – сосуды с тонкими пластинами меди внутри
Persian – a person from ancient Persia, now called Iran.
Work in pairs.
Ask and answer the questions about the history of electricity.
Example: Student A: When did the word ‘electricity’ first appear in print?
Student B: Well, I think it was first used in the book “Pseudodoxia Epidemica” in 1664
9 Match the words 1-8 with the definitions a-h
1 phenomenon a the force that works against an object as it slides along the surface
2 discovery b the amount of electricity that an electrical device stores or carries
3 friction c a fact or an event in nature or society
4 charge d the speed at which something is travelling
5 velocity e a statement showing that two amounts or values are equal
6 equation f the set of tools, clothing, etc., needed for a particular activity
7 equipment g the act of finding something that had not been known before
8 lightning h a flash of bright light in the sky produced by electricity moving between
clouds or between clouds and the ground
10 Form the related nouns. Then make sentences using these verbs or nouns.
1 investigate - investigation
2 calculate - __________
3 develop - __________
4 introduce - __________
5 describe - __________
6 appear - __________
11 Read the information and correct 10 spelling mistakes in it.
In the history of electricity, no single defining moment exists. The way we produse, distribut,
and use electricity and the devises it powers is the culmination of nearly 300 years of reserch
and develepment.
Efforts to understend, capture, and teme electricity began in the 18th century. For the next 150
years, dozens of sientists in England, Europe and latter in the United States analysed electricity
in nature, but produsing it outside of nature was another mater.
12 Watch the video “The Present Perfect Tense ”. Then use the sentences below to complete the rules.
- I haven’t seen you for ages.
- I haven’tread the letter yet.
- She has returned from England this week.
- She hasworked here since 2015.
- I have seen her today.
- Let’s go, it has already stopped raining.
- Where have you been?
- I have just beenasked to help arrange the conference.
Present perfect
FORM
Affirmative sentences
Usehave/has + past participle
I/You/We/They ___________
He/She/It ___________
Negative sentences
Use haven’t/hasn’t + past participle
_____________________________
Questions
Change the word order
_____________________________
Passive forms
Use have/has +been + past participle
______________________________
USE
1 We use the present perfect to speak about the past and the present together.
We use it when the speaker is interested in the mere fact that the action took place, but not in the time
when it took place.
__________________________________.
2 When the speaker means that, though the action is over, the period of time within which it was performed
is not yet over at the moment of speaking (with the words today, this week, this year, etc.)
___________________________________-.
___________________________________
3 We use the present perfect to denote actions which began before the moment of speaking and go on into it.
In this case either the starting point of the action is specified (since)
or the period during which it continued (for).
___________________________________
___________________________________
Past simple & present perfect
We use both these tenses to describe actions that started or ended in the past. Which tense we select
depends on whether:
a) we are referring to a definite or indefinite time
b) the action is finished or unfinished
We often use adverbs like recently, already, yet, never, just and time expressions for and since
with thepresentperfect.
We often use time expressions like yesterday, ago, last week/month/year etc with the past tense
Example: I’ve never been to Rome before, but I’m going next year.
I didn’t sleep a single moment thatnight.
13 Complete the sentences with the correct form of the present perfect or the past simple.
1 The present day’s urgency in achieving environmental sustainability _______(promote) renewed
interest on gathering inspiration from nature in order to create novel design concepts.
2 Electricity ______(be) a subject of scientific interest since at least the seventeenth century.
3 In the 19th century the subject of electrical engineering with tools of modern research techniques,
__________(start) to intensify
4 Electricity is used with telecommunications, and indeed the electrical telegraph, demonstrated
in 1837 by Cooke and Wheatstone _____(be) one of its earliest applications.
5 Electricity is the best source of energy. While there are other sources of energy none of them
__________(reach) the stage where they can be used to provide the power to help modern life go.
6 The processes used to produce electricity using the sun’s energy historically ________(be) more
expensive than using conventional fossil fuels.
7 In 2015, less than 1% of the nation’s electricity __________(supply) by solar power.
8 In 1827 Georg Simon Ohm _________ (quantify) the relation between electrical current and potential
difference between conductors – leading to Ohm’s law.
14 Make up situations to justify the use of the present perfect or the past indefinite.
1 Have you read the paper this morning?
Did you read the paper this morning?
2 He hascalled me up from London three times this week.
He called me up from London three times this week.
3 I’vehad a letter from him today.
I had a letter from him today.
4 I’vemet them both this afternoon,
I met them both this afternoon.
15 Choose the correct alternative.
1 For centuries natural scientists and engineers have inspired /have been inspired by life’s devices.
2 A number of design methods, intended especially to guide industrial designers in carrying out
the development of biologically inspired design, have been proposed /have proposed.
3 Taking a leaf out of nature’s book, scientists have developed/ have been developed technologies that
seek to mimic some of life’s unique innovations.
4 Electrical phenomena have studied/ have been studied/ has been studied since antiquity, though
advances in the science were not made until the seventeenth and eighteenth centuries.
5 Electricity is an extremely flexible form of energy, and has adapted/has been adapted to a huge and
growing number of uses.
6 Optical fibre and satellite communication technology have taken/have been taken a share of the market
for communication systems, but electricity can be expected to remain as essential part of the process.
7 Volta discovered that chemical reactions could be used to create cathodes and anodes. The difference
of electric potentials between them could lead to the flow of a current between them. The unit of
potential difference has been named/has named as ‘volt’ in his honour.
8 Coulomb mathematically articulated the attraction between electrified bodies. This laid /was laid
the foundation of quantitative study of electricity.
16 Look at the examples and complete the rules. Write for or since.
I haven’t seen you since we left university.
I haven’t seen you for ages.
Rules.
1 We use __________ to say when an activity started.
2 We use __________ to say how long an activity has continued.
3 We use _____ with a period of time and ______ with a point in time.
17 Complete these sentences with for or since
1 I’ve been a student… two years.
2 We haven’t had any rain … a very long time.
3 That building’s been there …the 19th century.
4 We’ve only been here …two minutes.
5 I haven’t seen you … the last conference.
6 I’ve worked for the same company … 2012
7 We’ve been very successful …we operated a store in China.
8 He’s been the team leader… ten months.
18 Work in pairs or small groups. Find out if your partner(s) have ever done the things on your list.
Use the past simple when you start talking about the definite time.
Example: A: Have you ever been to China? A: Have you already seen the iPhone 7?
B: No, I haven’t. What about you? B: No, I haven’t.
A: Oh, I’ve been twice. A: Neither have I. But I saw the presentation yesterday.
B: Where did you go exactly? B: Have they made any interesting improvements?
A: I went to Beijing and Shanghai. A: Yes, the iPhone 7 plus has a dual camera which is
great for taking pictures and wireless earphones.
19 Complete the sentences.
1 I’ve lived at my present address for…
2 I’ve studied English since…
3 I’ve haven’t been to party since…
4 I’ve known my best friend for…
5 I haven’t had a holiday for…
6 I haven’t had anything to eat since…
20 Work in pairs and play a True/False game. In this game write sentences about five events in your
life. Three events must be true and two should be false. Ask each other three questions about each
event. The partner then decides which events are true and which are false.
Example: Student A: I’ve met a famous sports star.
Student B: Who did you meet?
Where did you meet him/her?
What did you say to him/ her?