information. You need to analyse and describe this information clearly and accurately. When

your paper is marked, the examiner will be assessing your grammar and vocabulary. In

this video we'll focus on the language you'll use to write your sentences.

Often you'll need to describe the trends in the data, that is how the figures change over

time. You will also need to make comparisons between different elements given in the graph

or graphs. This means you'll write about how data is similar or different. Let's

look at an example.

This line graph is about global energy consumption since 1970 by generating method. The vertical

axis shows percentage figures, and the horizontal axis shows the years since 1970.

We can identify two overall trends: the slight decrease in consumption of energy from petroleum

and coal, and the slight increase in energy generated by gas and nuclear energy. We would

mention these overall trends in the overview.

Now, we need to write about this in more detail. When we do this, we must mention the data

to support the description. Let's begin with the energy source with the highest consumption,

petroleum. We'll use three expressions: 'peaked at over 50%', 'gradually declined';

and 'has remained stable'. Let's use these to make our sentences. The consumption

of petroleum peaked at over 50% in 1973, then gradually declined over the next 12 years.

Since 1985, global petroleum consumption has remained stable at 40%. Remember, it's very

important to include data from the graph.

Now, let's look at the global consumption of nuclear energy. Can you think of some words

to describe this pattern? Did you think of these phrases? Notice that you need to carefully

choose your tense to match the time. We'll use past simple for finished time in the past.

And we'll use present perfect for time beginning in the past, but continuing until now. Let's

put these phrases together.

For the first decade after 1970, the rate of nuclear energy consumption was unchanged

at around 5% worldwide. After 1980, it slowly increased, and since 1995 it has plateaued

at 12%. Notice that rather than repeating 'the rate of nuclear energy consumption',

we can say 'it'. This improves cohesion.

So, we've looked at how you might describe trends, that is, how something changes over

time. Usually, we'll see this in line graphs like the one we were looking at, but we could

also see trends in charts or even tables. Next, we'll focus on how to make comparisons

by describing similarities and differences in something in fixed time. For this, we'll

look at a pie chart.

This pie chart shows us which languages English originated from.

It's important to note that pie charts give information about the whole of something,

in this case, the English language. We can see the parts which make up the whole, or

100%. In an overview we would try to group the data to make a statement. We could say

that three languages Germanic Languages, French and Latin, had the greatest influence in roughly

equal proportions, and much less influence came from Greek, Other Languages and the names

of people and places.

So, let's look at how we would compare each of these six influences on English. We'll

write about the dominant group first. We can see that the influence of French and Latin

is exactly the same at 29%, and that of Germanic Languages is almost as much at 26%. All three

of these languages together make up more than 80% of the origins of English. Let's write

this into sentences.

Remember that it is very important that we give data from the chart in our sentences.

Also look at how we change the use of the word 'influence' from a noun to a verb.

This shows the examiner that you are flexible in vocabulary use.

We still need to mention the smaller sections of the pie chart. Clearly, the influence of

these groups is smaller than French, Latin or Germanic Languages. We should think

of words to say how much smaller. We could say considerably smaller, or significantly

smaller.

Here's a short sentence about this. It begins with a linking expression to show that we're

moving from the more influential languages to these smaller groups of languages.

The beginning of this sentence lists three parts of the pie chart: Greek, other languages

and proper names. Then at the end, we gave the percentage figures for each of these languages

or language groups. Notice that these figures were given in the same order as the languages.

So the figure for the first language, Greek, is the first figure, 6%, and so on.

To make this clear to the reader, we use the word 'respectively' at the end of the

list. This technique works well for two or three items, but not more than that.

In this video we've looked at language for describing trends, or changes over time, in

the example of a chart about energy consumption, and we've seen the example of the pie chart

where we needed to compare the influence of languages on English. I've shown you just

a small sample of the kind of language you will use in Task 1 of the IELTS Academic Writing

Test. It's a good idea for you to build your vocabulary for this kind of writing before

you do the test. Now you will have the chance to practise some language for describing data.