not only have they/they have improved


Spanish (Spain)
hello everyone,

Is it compulsary to make subject-verb inversion if we start a sentence with "not only"?

e.g. Not only have they improved their musical knowledge, but they have also been in contact with new instruments".

or: Not only they have improved their....

I have looked for examples in the internet, but either both ways are correct, or either they were mistakes.

Thank you!
  • mhp

    Senior Member
    American English
    Tough question!

    The most common practice is to make the inversion. Is it obligatory? I don't know, but I can tell you that the sentence sound better with the inversion.
    Last edited:


    Senior Member
    US, English
    Yes, it is obligatory. The rules are the same as for questions or negations. Not only do you have to invert the sentence, but you also have to use the auxiliar 'do' when the main verb itself is not auxiliar, modal or copulative:

    Not only does she go to school every day, she works full time too.
    *Not only goes she to school...

    You can, however, avoid this issue by putting 'not only' between the subject and the verb.

    She not only goes to school every day, she works full time to.


    Spanish (Spain)
    Thank you for the information. Do you think that the sentense with the inversion sounds more formal? Or can I use it in normal language?