On a grammatical level, this cursory list suggests that Clinton is more likely to use keywords that are substantive and concrete. She mentions men, women, children, Americans, students, and teachers, while Trump uses more pronouns like I, they, me, anybody, somebody, nobody, people and folks.
Clinton also uses stronger verbs like deserve, create, and invest, while Trump uses going, are, got, and is.
Clinton talks about growth, responsibility, challenges and threats, while Trump uses the words great, bigger, problems, and worst.
When it comes to Trump’s rhetoric, what is perhaps most striking is the frequency with which he references himself. He says I, me, or my 850 times in these seven speeches. (He says I 700 times, me 94 times, my 56 times, mine 5 times, and myself 2 times out of the total 25,722 words in the corpus.) What this means is that 3.3% of his words are self-references, which is a remarkably high figure by the standards of any typical corpus.
By way of comparison, Clinton says I 360 times, me 36 times, and my 52 times out of the total 23,089 words, bringing the total percentage of explicit self-references to 1.9%.
Another difference between the two is that Trump, unlike Clinton, refers to himself in the third person. For instance, “Nobody would be tougher on ISIS than Donald Trump. Nobody.” Or, “…the chances of peace really rise and rises exponentially. That’s what will happen when Donald Trump is president of the United States.”
Trump’s narcissism has already been pointed out by others, but it is strikingly distilled even in a cursory linguistic analysis.
–Katelyn Guichelaar and Kristin Du Mez, Donald Trump and Hillary Clinton, By Their Words
h/t Alan Jacobs