It allows you to use sophisticated words to persuade
Explanation:
When you write a persuasive essay you want to sound and speak very maturely. Most people will read certain things if the person knows what they are talking about.
A persuasive essay (also called an argumentative essay) is a type of essay written to convince readers to believe in an idea or opinion and perform an action. When writing a persuasive essay, you should use logic and reason to prove that your point of view is the correct one. Your arguments should be supported by convincing facts.
Besides that, it's very important to pay attention to the conventions of the language you are writing your essay in. We are more likely to believe someone who uses correct grammar than someone who makes mistakes. That is how proper language lends credibility to your paper.
I assume that the blank -- which you did not provide -- occupies the 'verb' position in the sentence. If so, then here are some examples I have brainstormed .....