Most US presidential candidates are using grammar and vocabulary typical of children in middle school, with Republican front-runner Donald Trump the worst offender, a new study has found.
A readability analysis of presidential candidate speeches by researchers in Carnegie Mellon University's Language Technologies Institute (LTI) found most candidates using words and grammar typical of students in grades 6-8, though Trump tends to lag behind the others.
A historical review of their word and grammar use suggests all of the five candidates in the analysis - Republicans Trump, Ted Cruz and Marco Rubio, and Democrats Hillary Clinton and Bernie Sanders - have been using simpler language as the campaigns have progressed.
Trump is an outlier, with his grammar use spiking in his Iowa Caucus concession speeches and his word and grammar use plummeting again during his Nevada Caucus victory speech, researchers said about the billionaire real-estate baron.
A comparison of the candidates with previous presidents shows Abraham Lincoln outpacing them all, boasting grammar at the 11th grade level, while George W Bush's 5th grade grammar was below even that of Trump.
"Assessing the readability of campaign speeches is a little tricky because most measures are geared to the written word, yet text is very different from the spoken word," said Maxine Eskenazi, LTI principal systems scientist.
"When we speak, we usually use less structured language with shorter sentences," said Eskenazi, who performed the analysis with Elliot Schumacher, a graduate student in language technologies.
An earlier analysis by the Boston Globe used the Flesch-Kincaid readability test, which is based on average sentence length and average number of syllables per word, and found Trump speaking at a 4th grade level, two grade levels below his peers.
Eskenazi and Schumacher used a readability model called REAP, which looks at how often words and grammatical constructs are used at each grade level and thus corresponds better to analysis of spoken language.
Based on vocabulary, campaign trail speeches by past and present presidents — Lincoln, Reagan, Bill Clinton and Barack Obama - were at least on the 8th grade level, while the current candidates ranged from Trump's 7th grade level to Sanders' 10th grade level.
Trump and Hillary Clinton's speeches showed the greatest variation, suggesting they may work harder than the others in tailoring speeches to particular audiences, Schumacher said.
In terms of grammar, none of the presidents and presidential candidates could compare with Lincoln's Gettysburg Address - an admittedly high standard, with grammar well above the 10th grade level.
The current candidates generally had scores between 6th and 7th grades, with Trump just below 6th grade level. Bush scored at a 5th grade level.
