The writing skills are complex

[aksamgunesi]

The writing skills are complex and sometimes difficult to teach, requiring mastery not only of grammatical devices but also of conceptual and judgmental elements.

Is this sentence correct as gramatically?
I didn't get why we need to use 'of' here after not only and but also.

 

[teechar]

Re: Is it correct?

Is this sentence correct [STRIKE]as[/STRIKE] grammatically?

Yes, but I doubt that you need "the" at the start of it. [Note that I crossed out "as"]

I [STRIKE]didn't[/STRIKE] don't get why we need to use 'of' here after 'not only' and 'but also'.

You don't. The second "of" is optional.

 

[jutfrank]

Re: Is it correct?

There are two types of mastery.

1) mastery of grammatical devices
2) mastery of conceptual and judgemental elements

The word mastery has been omitted the second time, but the preposition remains to help the reader understand the omission.

 

[GoesStation]

Re: Is it correct?

I didn't get why we need to use 'of' here after not only and but also.

The string of words "after not only and but also" is nearly impossible to understand. Always mark the words or text you're writing about with quotation marks or italics.

 

[Tdol]

Re: Is it correct?

Yes, but I doubt that you need "the" at the start of it.

Unless these are very specific, restricted skills, I doubt it too.