Page 617 - Practical English Usage 3ed - Michael Swan, Oxford

This and that are more emphatic; they 'shine alight', so to speak, on the things or situations, suggesting 'an interesting new fact has been mentioned'.
So she decided to paint her house pink. ThislThat really upset the neighbours, as you can imagine.
This is preferred when there is more to say about the new subject of discussion.
So she decided to paint her house pink. This upset the neighbours so much that they took her to court, believe it or not. The case came up last week ... Then in 1917 he met Andrew Lewis. This was a turning point in his career:
the two men entered into a partnership which lasted until 1946, and ... (More natural than ... That was a turning point . ..)
2 more than one thing
When more than one thing has been mentioned, it generally refers to the main subject of discussion; this and that generally refer to a new subject that has been introduced (often the last thing mentioned). Compare:
-
-
We keep the ice-cream machine in the spare room. It is mainly used by the children, incidentally. (The machine is used by the children.)
We keep the ice-cream machine in the spare room. This/That is mainly used by the children, incidentally. (The spare room is used by the children.) 1 was carrying the computer to my office when 1 dropped it on the kitchen
table. It was badly damaged. (The computer was damaged.)
1 was carrying the computer to my office when 1 dropped it on the kitchen
table. This was badly damaged. (The table was damaged.) 3 focus
It is only used to refer to things which are 'in focus' - which have already been talked about. This is preferred when we 'bring things into focus' before anything has been said about them. Compare:
I enjoyed 'Vampires' Picnic'. It/This is a film for all the family . .. VAMPIRES' PICNIC: This is a film for all the family ...
(NOT ~rAM?{RES' P1CNW. It is flJilm for flll the family . ..) 4 referring forward
Only this can refer forward to something that has not yet been mentioned. Now what do you think about this? 1 thought I'd get a job in Spain for six
months, and then . .. (NOT N8ft1 ftlhat tl8 )'81:1 think ab6l:1t that/it . ..) For more about this and that and the differences between them, see 589.
For more about it. see 428.
591 This is the first/last ... etc 1 This is the first time etc
We use the present perfect in sentences constructed with this/it/that is thefirst/ secondlthird/only/best/worst etc.
This is the first time that l'ue heard her sing. (NOT This is theft,st time #tat >'
hear ,'16 sing.)
~
This is the firstllast ... etc 591
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