I was recently invited to give a lecture on my research in Washington, DC. As a sociolinguist, I study the science of language in its social context. I began my lecture by describing the different ways that linguists subcategorize languages. Dialects, which most people are familiar with, are regional varieties of a language, like Texan or Midwestern English. But there are also ethnolects, associated with specific ethnic groups, like Chicano and Jewish English, and genderlects, which refer to the distinctive ways that women and men talk.

Then I introduced the term “idiolect.” Before I had a chance to define it, an audience member quipped, “Is that the way that idiots like Donald Trump talk?”

An idiolect is not the language of idiots, but an idiosyncratic form of language that is unique to an individual. No two individuals—not even family members living under the same roof—speak the exact same language. We all pronounce words slightly differently, have different inflections in our voices, and choose different words to refer to the same thing. After my speech, for example, I asked where I could find the “bubbler” (a relic of my Bostonian upbringing). My host showed me the way to the “water fountain.”

The audience member was right when he suggested that Donald Trump speaks an idiolect, because Trump is human. But in his case, the way he speaks produces strong reactions in his listeners—especially since his idiolect is accompanied by a larger-than-life (“yuuge”) personality.

As a linguist, my job is not to evaluate which idiolects are better than others. A central principle of linguistics is that no variety of a language is inherently better or worse than any other. All varieties, from what you hear on NPR to what you see in online responses to YouTube videos, exhibit patterns that linguists have spent decades documenting. But to say that all language varieties are equally valid systems of communication does not mean that they are equally valued in society.

And nowhere is the principle of idiolect evaluation more important than in politics, where we judge candidates almost entirely based on talk. Whether we are watching debates or interviews, or reading policy statements or tweets, everything we know about political candidates is filtered through a linguistic lens. And the type of language used—especially candidates’ idiolects in their public appearances—contributes to our evaluations of what I call their “presidential selves.”

Donald Trump’s idiolect has been at the heart of what many see as his enigmatic and disconcerting rise to front-runner status in the Republican primaries. The most common negative impressions of Trump’s idiolect I hear are: “He doesn’t make any sense.” “He uses a lot of small words.” “His speeches are non-substantive.” On the other hand, Trump has garnered many supporters who are drawn precisely to his message. Their impressions of his idiolect are phrased quite differently: he’s “authentic,” “relatable,” and “consistent.” He’s a “straight shooter” who “doesn’t mince words.”

So how does one idiolect produce such polarizing evaluations? It has to do with the precarious connections between linguistic form and meaning. The relationship between the two, as the anthropologist Elinor Ochs describes, is non-exclusive, indirect, and constitutive. Put simply, there are multiple meanings associated with any given linguistic feature, and the connection between form and meaning is a two-way street with a lot of roundabouts. For example, pronouncing tomato as “tomahto” can lead listeners to believe that you are British or that you are snooty. And if I happen to think that you are snooty, I may give your voice a British flair when I imitate you (“And then she ordered a bacon, lettuce, and tomahto sandwich!”), even if you’ve always pronounced your fruits and vegetables in the American way.

Whichever meaning is activated by a specific pronunciation, or any other aspect of your idiolect, has everything to do with context: Where are you? Who is your audience? What is your purpose? What image are you trying to project? These are factors that candidates are always taking into account as they put forth their presidential selves on the campaign trail. Tailoring their speech to the context, like when a candidate takes on a drawl while campaigning in the South, has been grounds for being labeled “inconsistent” or “fake,” as we’ve seen with Hillary Clinton, even though this type of linguistic accommodation is a perfectly natural feature of everyone’s idiolect.

However, linguistic explanations of social context fall short when explaining how one person’s idiolect can generate multiple contrasting meanings when everybody is watching the same speech. How does half of the population come away from the same event thinking Donald Trump sounded like a bumbling idiot, while the other half praises his performance as authentic and indicative of a strong leader?

An equally important factor in guiding idiolect evaluations is that of experiential context, which has to do with individual preferences based on our personal experiences with language. For example, while a working-class Italian-American dialect gives the impression of “mobster” to many, it gives me a warm, fuzzy feeling that I associate with my childhood.

As it relates to Donald Trump’s idiolect, let us take the frequent criticism that he is incoherent, which stems in part from his distinctive topic-shifting patterns in his speeches. Trump often introduces topics abruptly with non-substantive words (which linguists call “discourse markers”) like “so,” “you know,” or “anyway.” These are words that everyone uses in everyday conversation, and while they have little referential value on their own, linguists have shown that they play an important role in the organization of talk. In fact, without them, conversation sounds stilted and unnatural.

When Mr. Trump gives a speech, viewers notice his distinctive idiolectal use of discourse markers, which also give the impression that he is having an intimate conversation with individual voters rather than giving a prepared speech to a mass audience. This off-the-cuff, unrehearsed style also gives the impression that Trump is speaking for himself and not from a speechwriter’s script (a point he explicitly makes), which contributes to what his supporters describe as his “authentic,” “trustworthy,” and “relatable” character—all important qualities to cultivate in a presidential self. On the other hand, when others hear this same idiolect, they connect these conversational devices with social meanings like “casual,” “unreflective,” “unprepared,” and even “reckless”—certainly not qualities of an ideal presidential self.

What guides our impressions in one direction or the other is in part our personal experiences with language, and how we rank and connect values like “authenticity” and “seriousness” with language in our estimations of presidential candidates. However, research has also shown that voters’ evaluations of whether candidates’ speeches make sense depend on whether they already support a candidate. So while Donald Trump’s idiolect may help him win voters because of its appeal to “authenticity,” at another level it doesn’t matter: voters who like him for other reasons will find coherence in whatever he says and however he says it.

This view may seem overly deterministic, but it is important to keep in mind the context factor. While idiolects may play an important role in whittling down a field of candidates during the primary season, insofar as they work toward brand distinction among a multitude of candidates whose views are not substantially distinct, voters will likely be paying attention to other things in November, and may be recalibrating the values and language they deem most presidential.