In normal declarative English sentences, let's call them 'canonical' sentences, the verb comes after the subject.

  • Bob is walking the Great Wall of China.
  • Bob likes elephants.

But in other types of construction and in certain other situations the auxiliary verb comes before the subject. One notable instance is in questions:

  • Is Bob walking the Great Wall of China?

Here we se the auxiliary verb BE occurring before the Subject. If there is no auxiliary verb in the normal declarative version of the sentence then we need to insert the auxiliary DO:

  • Does Bob like elephants?

My question here is twofold. Firstly:

  1. What are the different constructions or environments in which either we require subject-auxiliary inversion in modern English, or can optionally use it?*

Secondly, and more importantly:

  1. Is there any generalisaton we can make about these constructions. Does subject-auxiliary inversion have some kind of meaning in all of these, or a subset of these?

*Not including poetry, for obvious reasons.

  • 1
    There is a more comprehensive list probably here: udel.edu/~bruening/Downloads/SubjAuxInvSyncom2.pdf - anyway, good luck.
    – user 66974
    Commented Oct 19, 2018 at 18:50
  • 1
    Your post reminds me of a question that consistently occurs to me when I see Real Linguists™ converse here on EL&U: why do you guys Capitalize Terms For Parts of Speech?
    – Dan Bron
    Commented Oct 19, 2018 at 19:08
  • 3
    @DanBron To distinguish them from parts of speech! In my posts, parts of speech are all in lower case and grammatical relations/functions have initial capitals. That's because it can be really difficult to distinguish the two if you don't keep a handle on it. So Subject has a capital, but noun does not (in the convention that I use). This becomes important with things like Determiner and determinative -- where some other people use Determinative for the function and determiner for the part of speech! Commented Oct 19, 2018 at 19:12
  • 2
    That's the same as a real linguist. Trust me, I know. You're welcome to whatever lists I've emitted in the course of generating these posts. Commented Oct 19, 2018 at 19:15
  • 2
    @JohnLawler Thanks, that's greatly appreciated. (Your resources are always useful and greatly appreciated!) Commented Oct 19, 2018 at 19:17

3 Answers 3


The only time outside of poetry that I can think of where it is not optional would be in the so-called tag question.

Bob likes elephants, doesn't he?


Offhand, I can only think of two, uh, constructions ... or environments:

Not only did they dislike verismo opera intensely, they weren't even remotely interested in music as an art form.

And this, from Robert Louis Stevenson's Heather Ale:

The king rode, and was angry.
Black was his brow and pale:
To rule in a land of heather
And lack the Heather Ale.

  • Thanks, but what situations/constructions characterise the two examples that you give? So, for illustration, I described one situation in my post as "questions". Commented Oct 19, 2018 at 19:52
  • What can I tell you! I have no idea how to describe the situation in the first example, even though the construction is fairly common even in everyday speech. As for the second example, poetry would lose a great deal of its charm if you had to explain every linguistic twist it contains.
    – Ricky
    Commented Oct 19, 2018 at 20:01
  • 1
    Your comments are poetic in themselves. I'd like them to be preserved. Please don't delete them.
    – Ricky
    Commented Oct 19, 2018 at 20:28

Bob likes elephants. 

Sure, this is in canonical order with an S/V/O pattern.  It's also indicative and declarative. 


Does Bob like elephants? 

This isn't declarative.  It's interrogative. 


Should Bob like elephants, we can plan a visit to the zoo. 

This isn't indicative, although it might not be fashionable to call it subjunctive anymore. 


Not only does Bob like elephants, he practically worships them. 

This still feels indicative and declarative, but the entire clause is negated from the outside.  It's not as straightforward an indicative declaration as it is when it stands on its own.  If the clause including its external negation seems indicative, then the clause per se, excluding that qualification, may well be something else. 


One thing that traditional grammar gets wrong is the way it lumps its declarative/interrogative distinction in along with its indicative/subjunctive distinction.  There's a tangle of two or three orthogonal properties that are traditionally labeled mode: indicative, interrogative, subjunctive, exclamatory and imperative are values that all leap to mind. 

Something pulled that snarl together.  This inversion marks some non-default value in that tangled mess.  Do I think that it's a likely candidate?  Do I ever!

  • Can you explain the difference between "declarative sentence" and "indicative sentence"? And is this distinction widely accepted (I personally had thought the terms to be perfect synonyms)? Commented Apr 3, 2020 at 7:59
  • Can I explain it? -- that's an indicative and interrogative clause. Perhaps I could offer examples. -- that's a subjunctive and declarative clause. I'll leave it to you to construct the matching subjunctive-interrogative and indicative-declarative examples. Commented Apr 3, 2020 at 15:33

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.