Use of which in a sentence

Question

In the following sentences, is it necessary to use which?

SRH, a recombination model, is used for direct bandgap materials.
SRH, which is a recombination model, is used for direct bandgap semiconductors.

If both are correct, please explain the use of which in those cases.

Both of the sentence are grammatical; in other words, you don't have to use which is (here is a missing is as well). Together they make up which is, a typical target for the syntactic rule Whiz-Deletion. Like all syntactic rules, this doesn't change the meaning. — John Lawler, Aug 25 '20 at 14:52

Edwin Ashworth · Answer 1 · 2020-08-25T14:04:49.267

1

The two variants are both grammatical.

(1) has 'a recombination model' (correctly offset, as it is a non-defining parenthetical, by commas) as an explicative / descriptive appositive.

(2) uses a non-defining relative clause (correctly, as it is non-defining, set off by commas) to add the additional information.

edited Aug 25 '20 at 14:04

answered Aug 25 '20 at 13:58

Edwin Ashworth

83,272

Please let me know the usage situation of those two cases. – Bharath Reddy Aug 25 '20 at 14:09
I'd say they're virtually identical in their distribution. Neither would give rise to the slightest raising of an eyebrow. – Edwin Ashworth Aug 25 '20 at 15:02

score 1 · Answer 2 · answered Aug 25 '20 at 14:12

Both are correct.

In 1, “SRH” and “a recombination model” are in apposition, suggesting an equivalence between them. The equivalence need only be partial. Thus, all that we know about SRH is that it is a member of the set of recombination models; all we know about the set of recombination models is that it contains SRH. The same analysis could be done with “I saw a tree, a green thing” or “I saw a green thing, a tree”. In each example the overlap of equivalence is partial.

In 2, “which is a recombination model” is separated from the main flow of meaning (“SRH is used ...”) by commas. It is therefore a supplementary clause that qualifies SRH. The logical considerations of partial equivalence still apply.

I conclude that both are clear, unambiguous and correct and that there is no difference in meaning.

Use of which in a sentence

2 Answers2