# Is there a rule for determining which 'wh'(i.e.,when,where) to use?

Recently, I have read a lot of sentences about the use of 'that is'(i.e.), and it really confuses me.

Here are two examples:

1. The question given below consists of six statements followed by options consisting of three statements put together in a specific order. Choose the option which indicates a valid argument containing logically related statements, that is, where the third statement is a conclusion drawn from the preceding two statements.

2. In this book the meaning of 'quantifier' is slightly different. It refers to words that can be used in a particular pattern, that is, when they are followed by 'of' and then a definite noun group.

I am trying to figure out how the 'where'(in sentence 1) and the 'when'(in sentence 2) work. Here is my reasoning:

1. In sentence 1, 'where' is used to specify 'consisting of three statements put together in a specific order' which acts as an abstract position.
2. In sentence 2, 'when' is used to specify 'in a particular pattern' which acts as a condition.

Is this reasoning suitable? If not, how to analyze these sentences?

In (1), where introduces a clarification of what they mean by 'indicating a valid argument containing logically related statements'.

You are correct in saying that, in (2), when specifies what the 'particular pattern' is.

• Could you give some methods about how to determine the 'wh's? Or,some technical terms about this field. Thanks very very much! Commented Sep 8, 2023 at 13:44
• I don't know any technical terms for it, but my instinct tells me that where is used in (1) because it's about choosing from a list of options (as though you put your finger on one and said "There! That's the right one), and when is used in (2) because it refers to a set of circumstances (a word is followed by 'of' and a noun group). Commented Sep 8, 2023 at 14:56
• "Where" and "when" are prepositions in fused relative constructions. The former has a paraphrase containing noun + integrated relative: *... in a case where the third statement is a conclusion drawn from the preceding two statements". Similarly the latter can be paraphrased "on occasions when they are followed by 'of' ...". Commented Sep 9, 2023 at 9:27

In both examples, the clause that you're asking about is an appositive.

In the first sentence, "where the third statement is a conclusion drawn from the preceding two statements" is an adverbial (or relative, if you want to think of it that way) clause in apposition to the relative clause "which indicates a valid argument containing logically related statements".

In the second sentence, the adverbial clause "when they are followed by 'of' and then a definite noun group" is in apposition to the adverbial phrase "in a particular pattern".

I consider "that is" to be a disjunct (part of a sentence that is not syntactically connected to the other parts). It could also be considered part of the last clause. In either case, it is nonrestrictive and thus surrounded by paired commas.

• But, appositives are always NPs, never clauses. Commented Sep 9, 2023 at 9:12
• @BillJ Yes, that's true are in your grammar. But not in mine. Commented Sep 9, 2023 at 17:17
• I can't get the linking to work properly. Wiki, Grammarly, Grammar Monster and Purdue talk only of NPs. Commented Sep 9, 2023 at 18:54
• @BillJ Yes, and there are other English websites that say the opposite, e.g. Linguistics Girl. The fact is that many professsional linguists note the possibility of other phrases serving as appositives, including our very own Edwin Ashworth: "There's an argument that any parenthetical in-line reformulatory/explanatory element is an appositive." Commented Sep 10, 2023 at 0:49
• I'd hardly call Linguistics Girl a reliable resource. And Edwin Ashworth is not a professional linguist. Btw, H&P talk only of NPs in their 'Big Book', of course. Commented Sep 10, 2023 at 7:37