Not only but also

[Meerak869]

In "not only but also" idiom i read in one source of gmat material which says 'but' is optional 'also' is compulsory. Is this true? If so in what cases?

Example sentence provided by that source:
In Emerson, Edgerton found someone who let him know that questioning orthodox beliefs was not only acceptable, also vital.

Please clarify......

[RonPurewal]

In "not only but also" idiom i read in one source of gmat material which says 'but' is optional 'also' is compulsory. Is this true? If so in what cases?

Example sentence provided by that source:
In Emerson, Edgerton found someone who let him know that questioning orthodox beliefs was not only acceptable, also vital.

Please clarify......

in the type of formal writing tested on the gmat, this sentence is incorrect.

what is this 'source of gmat material' that you're so reluctant to name?

[Yunxiao]

hi, Ron

not just by the fact that...but also by the fact that...
not just because of x, but because of y.

Is these sentence correct?

[RonPurewal]

those structures are fine (provided they contain things that are actually intended to be parallel).