Question: Recently an editor just changed the plural verbs in my essay to singular ones, but I don't understand why he did so. Please see below:

(Original sentence)
After rising to power through multiple revolutions, the Chinese Communist Party holds a subversive notion and ideology that not only **aspire** to break the old world, but also **aim** to build a new one.

(revised sentence)
After rising to power through multiple revolutions, the Chinese Communist Party holds a subversive notion and ideology that not only **aspires** to break the old world, but also **aims** to build a new one.

In my understanding, there are two nouns in "a subversive notion and ideology", and that should be followed by a plural verb?

Answer: 
The key is in the use of the indefinite article.

To paraphrase:

> 
> The CPP holds **a** subversive notion and ideology that **aspires** . . .
> 
> 
> 

I have put the subject in superscript in order to set it off from the rest of the text. Especially because of the ***a***, the syntax treats the phrase as a compound single subject.

It is the same idea as:

> 
> **This** fish and chips **is** delicious. 
> 
> 
> 

Although there are actually two separate things joined together, they are thought of, and treated as, a singular item.

---

In order for the syntax to show that there are *multiple* things being used as individual subjects, you would need to remove the indefinite article and pluralize the subjects:

> 
> The CPP holds subversive **notions** and **ideologies** that **aspire** . . .
> 
> 
> 

Alternatively, it's possible to use a phrasing similar to what follows—but it would be somewhat awkward:

> 
> The CPP holds **a** subversive notion ***as well as*** **a** subversive ideology that ***both*** aspire . . .
> 
> 
>
Yes. tchrist and Minty are right I think. But are both the notion and the ideology subversive? It isn't quite clear. And can a notion itself aspire to do something? Perhaps an ideology can, but I'm not sure. I would leave *notion* out, and say something like 

> 
> "The CCP's subversive ideologies suggest that it aspires not only to break the
>  old world but also to build a new one."
> 
> 
>