To an extent -I believe it is.
When I teach reading to my students I ask them to look for adjectives and verbs.
The adjectives and verbs directly describe the character, setting and conflict. I then use these skills when they write. When analyzing their writing I ask them, "Are you using your verbs and adjectives? Are you illustrating these important elements for your audience? - the reader?"
Verbs for example - your verbs will help you describe your characters actions. Are these actions expressed in the correct tense? Past or present.
adjectives help describe and illustrate the character, setting, tone and mood. An effective use of adjectives will provide a time frame, depth and sensory details for the reader.
Adjectives - I call these the spice that help season the nouns and verbs. These are the words that create imagery, tone and mood for the reader.
without the effective use of the above your writing may lose focus on the character and his/her motivations, relationships and conflicts.
If a writer can effectively answer who, what, when, where, how and why their respective characters are doing what they do - they are then using the parts of speech correctly.
I hope this helps :)