مجموعه Study English سری اول – قسمت 14

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Hello. I’m Margot Politis. Welcome to Study
English, IELTS preparation.

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Today we’re going to look at conditional sentences.
They’re sentences that use ‘if’.

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If you listen carefully, you’ll be able to
hear Dr Malcolm Simons talking about junk

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DNA, the parts of DNA that people used to
think were just rubbish. Listen to the different

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types of sentences he uses.

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Under Darwinistic notions, you would think
that junk would drop off under the theory

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of natural selection, just like species drop
off if they hit ecological niches, which is

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incompatible with survival. If they can adapt
to those niches, then those that can, survive,

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and those that can’t, die, is the notion.
If you apply that to the DNA sequence, then

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the coding region genes, which survive, have
a function, and by the way the non-coding

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sequences have survived as well. So the proposition
would have to be that if they’re there, they’ve

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got a function.

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In listening to Dr Simons, you can hear that
he uses a variety of sentences. This makes

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for much more interesting language. You should
practice using sentences of different lengths

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and types, especially complex sentences.

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Today we’re going to look at one of the ways
you can create complex sentences using an

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‘if clause’.

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An ‘if clause’ is a phrase that gives a condition
that’s necessary for something else to happen.

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They’re often called conditional clauses.

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If means when, provided that, or on condition
that.

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There are a few basic patterns for the ‘if
clause’.

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Listen to this:

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If they can adapt to those niches, then those
that can, survive, and those that can’t, die.

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So the proposition would have to be that if
they’re there, they’ve got a function.

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If they can adapt, then those that can survive.

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The pattern here is: if + simple present tense
verb, then ….

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Then introduces a clause describing the consequences.

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Look at the second example in the extract.

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If they are there, they have got a function.

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Notice that the then is left out in this example.
Then is optional.

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He could have said if they are there, then
they have a function.

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Let’s look at some more.

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If you have a university education, then you
have more opportunities.

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But the then is optional – you can leave it
out.

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If you have a university education, you have
more opportunities.

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Notice that this pattern can be reversed.

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You have more opportunities if you have a
university education.

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We never include then when the pattern is
reversed like this.

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Let’s try with the example from the story.

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If they’re there, they have a function.

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They have got a function, if they’re there.

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OK, now here’s the second pattern for ‘if’
sentences.

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This is for when the suggestion is less definite,
or less likely.

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If you had a university education, then you
would have more opportunities.

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The pattern here is: if + past tense, then
+ would + verb.

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If you had a university education, then you
would have more opportunities.

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We use this pattern when we are talking about
the future, and about something that may not

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be as likely to happen.

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Compare these 2 patterns.

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If you study hard, then you will pass your
test.

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If you studied hard, then you would pass your
test.

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In the first example, it’s a bit like making
a useful suggestion.

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The second sentence is less definite, and
less polite. It suggests that the person doesn’t

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study hard now.

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So that’s 2 ways of making the conditional
tense – how to say that one thing will happen,

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or might happen, if something else happens.
There are other forms of the conditional tense

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too.

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If you learn them, then your English will
improve!

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OK, now we’re going to look at ways of making
opposites by using prefixes.

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Listen to Dr Simons again.

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Under Darwinistic notions, you would think
that junk would drop off under the theory

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of natural selection, just like species drop
off if they hit ecological niches, which is

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incompatible with survival. If they can adapt
to those niches, then those that can, survive,

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and those that can’t, die, is the notion.

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If you apply that to the DNA sequence, then
the coding region genes, which survive, have

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a function and by the way the non-coding sequences
have survived as well.

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In the passage we heard the words survive
and die. They have opposite meanings.

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‘To survive’ means to keep on living and ‘to
die’ means to stop living. We call words with

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opposite meanings, opposites.

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Sometimes opposites are formed from the same
word stem using prefixes. Two of the prefixes

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he uses are ‘in’ and ‘non’.

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Listen:

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And by the way the non-coding sequences have
survived as well.

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He calls the junk DNA the non-coding sequences.

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Non-coding means not coding. Notice that we
use a hyphen with the non- prefix.

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Non- usually forms adjectives.

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It means ‘not in the group of’, so we have
non-European, non-Aboriginal or non-government.

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Non- can also just means not, giving a negative
sense to a word – non-fiction, non-smoking

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and non-stick.

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The prefix ‘in’ is used with adjectives as
well. It also makes opposites, and means ‘not’.

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It forms words like: insignificant, not significant;
inexpensive, not expensive; intolerant, not

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tolerant.

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Another common opposite prefix is un-.

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We can have unfair, unattractive, unusual,
unnatural.

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But un- can also be used with verbs. It means
that an action is reversed.

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So we have undo, undress or unbend.

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There aren’t many rules about what sorts of
words take these prefixes. You’ll have to

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learn most opposites one by one.

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A good way to do this is to try to find out
the opposite every time you come across a

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new word.

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Finally for today, let’s have a look at how
you can form adjectives from people’s names.

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Under Darwinistic notions, you would think
that junk would drop off under the theory

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of natural selection.

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He says under Darwinistic notions.

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Darwinistic here is an adjective, but it’s
got a capital letter – do you know why?

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Well, that’s because It comes from the name
‘Darwin’ – referring to Charles Darwin, who

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developed the theory of natural selection.

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But it’s got 2 suffixes: -ist and -ic.

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The -ic suffix forms adjectives that mean
belonging to, or like. So ‘Darwinistic’ means

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like a Darwinist.

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But a ‘Darwinist’?

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Well the suffix -ist forms adjectives too,
but it forms an adjective that describes a

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type of person with a certain set of beliefs.

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When -ist is added to people’s names, it means
someone who follows that person, or who believes

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in what they wrote or said.

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So we can have a Darwinist, someone who believes
in Darwin’s theories, or a Marxist, someone

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who follows the writings of Marx, or a Buddhist,
someone who follows the teachings of the Buddha.

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Well, we’re out of time for today. Remember
to watch out for those opposites, and try

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using ‘if’ clauses.

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See you next time. Bye
Bye.