0

I know when using not only ... but also ... we should follow parallelism. Ex: not only cats but also dogs, or not only run but also jump. However, I am confused which of the followings is correct and is it necessary to put comma before the but?

  1. Generally, a system is required to be not only stable but also stable by some margin of safety.
  2. Generally, a system is required not only be stable but also be stable by some margin of safety.
Improve this question
2
  • No 2 is missing a "to".
    – KillingTime
    Commented Aug 20, 2021 at 14:24
  • 1
    As @KillingTime said, #2 needs "to" after "required", or better after both "not only" and "but also". You could avoid the question and, in my opinion, improve the sentence with: "Generally a system is required to be stable, not just barely but with some margin of safety."
    – Andreas Blass
    Commented Aug 21, 2021 at 0:42

1 Answer 1

Reset to default
2

This is not a real parallelism, as the second part of this structure does not offer another element, but simply adds a circumstance to the already existing element. Not only can also be used before the verb. To emphasise that this is an addition and not a parallelism, I would say:

Generally, a system is not only required to be merely stable, but also be stable by some margin of safety. [you omitted this "to" in your second example]

This article shows the way this correlating conjunction is used and says that not all grammarians are so strict about it being used for parallelism only.

Improve this answer
2
  • thanks! So 1 is correct and in 2 can be modified using your suggestion, is it correct?
    – Lee
    Commented Aug 20, 2021 at 14:45
  • 1
    In numer 1 I would omit also to avoid ambiguity.
    – fev
    Commented Aug 20, 2021 at 14:51

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.