I have an exercise requiring us to complete a text with suitable reference words. Here is a small part of the text:
A further problem is the availability of software. Educational computer programs can be bought but these / such programs may not suit the needs of individual classes. Teachers can adapt such software to suit their needs in the classroom, but this is time-consuming and often complicated.
In the first blank, we can fill either these or such, but in the second one, there is only an acceptable answer which is such. Why can't we fill these in the second blank?
Best Answer
Concerning your exercise, the first case should be "these" in order to refer to the earlier mentioned "educational computer programs". The word "such" in this case can also be used and won't be incorrect either, however, it would mean "programs of the kind" and not particularly "these programs". Notice the difference:
With "these" we only refer to the books I have whereas with "such" we refer to any "rare book" (book of the kind) and it so happens that mine are of this very kind.
In the second case we can only use "such", since with the word "software" which is commonly singular, we can't use "these", only "this". "such" here means "similar software" or most probably "software of the kind" and conveys the kind of software that "**educational computer programs*" imply.