Cambridge Grammar of English Hardback with cd-rom a comprehensive Guide

Signalling with it, this and that

143a

Reference to textual segments is an important aspect of academic style. The

impersonal pronoun it and the demonstrative pronouns this and that are used in

different ways to organise references to text segments and are frequently not

interchangeable:

For example, 

interacting with native speakers

is obviously a Social Strategy,

but if 

it is part of an overall language learning plan, it could also be a

Metacognitive Strategy.

Low-luminance flickering patterns are perceived to modulate at relatively high

rates

. 

This occurs even though peak sensitivity is shifted to relatively low

temporal frequencies. 

(the whole of sentence one is the topic of sentence two)

(It occurs even though peak sensitivity is shifted to relatively low temporal

frequencies.)

[anatomy lecture]

And then that’s what’s called 

acoustic shadowing

, you see, 

nothing getting

through the back, there’s a black shadow behind it

. 

This is because this is a

densely calcified gallstone sitting in his gall bladder.

(This refers to ‘acoustic shadowing … nothing getting through the back, there’s

a black shadow behind it’ and makes those clauses the new topic for

discussion)

[genetics lecture]

As I say, you’ll learn more 

about the genetic codes which relate GAG to

glutamate and GUG to thyamine

in one of the other lectures in the course.

That is another way of expressing the flow of information from DNA to

proteins. Right. 

Û

128 for a full account of these uses of it, this and that

272 | Grammar and academic English

Cambridge Grammar of English

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