Firstly, there is no such thing as Microsoft WordPerfect9. WordPerfect9 was produced by Corel Corporation. Secondly, if I paste the phrase,
“I am trying to understand the connotations of this particular usage of the English language.”
, into my copy of WordPerfect, and run both the spell checker and the grammar checker, the sentence passes without a single error being flagged. Perhaps you could give the exact phrase that is being flagged by your software?