vocabulary or vocabularies

[tulipflower]

Is the use of the plural form of the word 'vocabulary' natural in the following sentence?
Since the students’ level is pre-intermediate, it is presumed that they know some of the vocabularies, their pronunciation, and their spelling.

 

[jutfrank]

No. Use the singular form.

 

[Tarheel]

What is meant by "some of the vocabulary"?

 

[emsr2d2]

Did you use "their" before "pronunciation" and "spelling" because you'd use the plural "vocabularies"?