Is the general word order of this sentence correct?

We investigate how strong the effect of X on Y is.

Or, as an alternative,

We investigate how strong the effect of X is on Y.

In a preprint for a scientific publication I came across the formulation:

We investigate how strong is the effect of XZY.

and now I'm all confused.

  • 2
    The first two sound okay to me, the last one sounds like something a non-native speaker would say. I would probably write something like, "We investigate the strength of the effect that X has on Y," or similar.
    – Cameron
    Commented Sep 4, 2012 at 22:46
  • Related.
    – tchrist
    Commented Jun 9, 2023 at 0:36

2 Answers 2


The Object clause how strong ..., since it starts with a Wh-word, is an Embedded Question Object Complement clause. Embedded Wh-Questions differ from real Wh-Questions in that they don't undergo Subject-Auxiliary Inversion.

So that's what lets out the third example, which has undergone Subject-Auxiliary Inversion.

Both of the first two examples are fine, because they both come from different potential placements of the prepositional phrase on Y. Being a locative adverbial, it can be inserted into any available niche in the sentence, including

  • The effect of X is Z on Y.
  • The effect of X on Y is Z.

Both of these, if "Z" is a real variable, coreferential with What, produce

  • What is the effect of X on Y?

as a non-embedded Wh-Question. However, as an Embedded question, either order is available, since the auxiliary verb is doesn't get inverted with the subject Noun Phrase the effect.


  1. We investigate how strong the effect of X on Y is -- OK.
  2. We investigate how strong the effect on Y of X is -- OK.
  3. We investigate how strong is the effect of X .. -- Not OK.
  • So you're saying that anastrophe is "Not OK" — ever?
    – Robusto
    Commented Sep 5, 2012 at 10:37
  • No, I didn't mention anastrophe. And saying this one is ungrammatical does not mean all anastrophe is. Anastrophe just means swapping word order; this construction is specific to swapping subject and first auxiliary verb in an embedded Wh-question. That's what's ungrammatical. Anastrophe is too general a term for grammar, since it doesn't distinguish constituents. Commented Sep 5, 2012 at 14:19

While I personally think the second example is stylistically strongest, there's nothing really wrong with the first. It just makes the reader parse "X on Y" as a prepositional phrase before getting to the copula, and "the effect of X" is easier to digest as a unit than "the effect of X on Y."

Moreover, although the third example may have an odd feel to it, there is still nothing wrong with that word order either. I can imagine the formulation being used to emphasize the word strength. (I'm not sure what XZY is supposed to mean; did you intend to write "X on Y" there as well?)

Imagine an expressive voice reading the line:

We investigate how strong is the effect of X on Y.

And consider a parallel construction:

We wonder how foolish is the man who thinks otherwise.

A little bit poetic, perhaps a bit dramatic — but certainly no glaring solecism to be worried about.


On the surface, this obviously conflicts with John Lawler's view about the third example. He is answering as a grammarian and for most uses his view on that example would be considered standard. I only mentioned my point about No. 3 because English is really more flexible than "standard grammar" would allow.

The "poetic" or "dramatic" effect I refer to is called anastrophe. It refers to an inversion of word order used for effect as a rhetorical device. From Ward Farnsworth's Classical English Rhetoric:

Some standard purposes of [anastrophe]:

a. The unexpected placement of words calls attention to them. Pushing a word into an especially early or late position often creates emphasis in itself; then the emphasis is still greater because the ordering mildly violates the reader's expectations.

b. Inversion may put words in an order that creates an attractive rhythm.

c. Inversion may compress a meaning into fewer words.

d. Inversion sometimes causes the full meaning of a sentence to become clear only late in its progress; this bit of suspense makes the finish more climactic when it arrives

That said, in most cases it would be safer to avoid anastrophe if you don't really know how to use it or intend to do so — to use it, as @AndrewLeach suggests, you first need to understand that you are deviating from a standard or "normal" word order.

  • 1
    Hm, you seem to disagree with John Lawler, who states below that the third form is wrong due to subject-auxiliary inversion. I'm a native German speaker, where word order is highly flexible, and was taught to be careful that it's much stricter in English...
    – Lagerbaer
    Commented Sep 5, 2012 at 3:13
  • The rules can be broken for dramatic effect (as Robusto notes in his answer); but it is necessary to realise the rules are being deliberately broken.
    – Andrew Leach
    Commented Sep 5, 2012 at 6:49
  • @Lagerbaer: See my addendum.
    – Robusto
    Commented Sep 5, 2012 at 10:50
  • @Robusto: embedded question no. 3, with subject-auxiliary inversion, is not grammatical in standard English writing. It does occur in speech, however, under certain pragmatic circumstances. Commented Sep 5, 2012 at 14:08
  • Well, for a written scientific report variation 3 would then be unsuitable :)
    – Lagerbaer
    Commented Sep 5, 2012 at 15:41

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.