Jennifer Sclafani, a linguist at Georgetown University, says President Trump is a "unique" politician because he doesn't speak like one. (Bastien Inzaurralde,Julio Negron,Kyle Barss/The Washington Post)

“Great people.” “Believe me.” “Not good.”

These two-word expressions are among some of the staples of the 45th president of the United States’ vocabulary. Although President Trump’s political career is just a few years old, he has already become associated with several simple phrases — “make America great again,” “build the wall” — and even single words — “win,” “sad,” “great.”

Trump is a “unique” politician because he doesn’t speak like one, according to Jennifer Sclafani, an associate teaching professor in Georgetown University’s Department of Linguistics.

“He is interesting to me linguistically because he speaks like everybody else,” said Sclafani, who has studied Trump’s language for the past two years. “And we’re not used to hearing that from a president. We’re used to hearing somebody speak who sounds much more educated, much smarter, much more refined than your everyday American.”

During a February news conference, Trump seemed to give credit to the power of his words for helping him become president.

“That’s how I won,” Trump told reporters gathered at the White House. “I won with news conference and probably speeches. I certainly didn’t win by people listening to you people, that’s for sure.”

Sclafani, who recently wrote a book set to publish this fall titled “Talking Donald Trump: A Sociolinguistic Study of Style, Metadiscourse, and Political Identity,” said Trump has used language to “create a brand” as a politician.

“President Trump creates a spectacle in the way that he speaks,” she said. “So it creates a feeling of strength for the nation, or it creates a sense of determination, a sense that he can get the job done through his use of hyperbole and directness.”

The features of Trump’s speech patterns include a casual tone, a simple vocabulary and grammar, repetitions, hyperbole and sudden switches of topics, according to Sclafani.

As for the criticism that Trump sounds erratic when he changes subjects in the middle of a speech or sentence, Sclafani said that “this is something that we all do in everyday speech.”

“It’s just unusual to hear it from a president speaking in a public, formal context,” she added.

Sclafani said Trump also sets himself apart by the words he doesn’t use. Trump started his sentences with “well” less frequently than other Republican contenders during the 2016 GOP primary debates, she said.

Omitting the word “well” at the start of a sentence helped Trump come across as a straight talker who wouldn’t try to escape a question asked by a moderator, Sclafani said.

“When we hear ‘well’ coming from other candidates, we’re more likely to perceive their responses as being dodgy,” she said. “And when we hear no ‘well’ from Donald Trump, we don’t notice that there is no ‘well’ there, but by contrast he comes off as sounding more straightforward and more direct.”

During a 2015 rally in South Carolina, Trump explained how he feels about his vocabulary.

“I know words,” he said. “I have the best words.”