What Kinds of Words Are “Yes” and “No” Anyway?

I’m usually fairly good with word classes, such as the differences between nouns, verbs, adjectives, adverbs and the like. But it recently struck me that I wasn’t sure how to classify “Yes” and “No”.

Specifically, I wasn’t sure what you’d class these words as when they’re used to respond to a binary question like “Do you know what kind of word ‘Yes’ and ‘No’ are?” Either word would constitute a complete response in itself. But how do you classify a word when it’s used in isolation like this?

Curiosity piqued, I did a bit of research. And here’s what I found.

“Yes” and “No” as Sentence Adverbs

Most of the dictionaries I checked (e.g. Merriam-Webster, Cambridge, Macmillan) class “Yes” and “No” as adverbs. But we tend to understand adverbs as modifying something. And since “Yes” and “No” can be used in isolation, it feels a little strange to say they’re modifying anything. So how does this work?

The idea here, as best I understand it, is that these words are adverbs that modify an entire sentence, or sentence adverbs.

The most familiar examples of these words are terms that we use to frame a sentence (e.g. “Generally, I like dogs”) or to show how clauses are related (e.g. “He did well. However, he could have done better”). And we can use “Yes” or “No” to respond to a question in a similar way.

For example, if you ask me if I want cake, I might respond by saying, “Yes, I want cake”. And the “Yes” here helps to frame the sentence as an affirmative.

Thus, when used with an echo answer like this, the adverb definition seems a good fit. But what about when “Yes” and “No” are used in isolation?

Given they are typically employed in dialogue, you could argue they’re modifying an echo response that’s understood tacitly from the context. Problem solved! But it still feels a bit strange to call these words adverbs for the unspoken.

Luckily, we have a few more options available for describing these words!

“Yes” and “No” as Interjections

One is as interjections (which is how the Oxford Learner’s Dictionary describes them). This typically refers to short utterances we make in response to something like surprise (“Wow!”) or pain (“Ouch!”). But while “Yes” and “No” can certainly be exclaimed, that’s not always the case. You might also say them hesitantly or after a long pause to think rather than express them suddenly.

Leornard Bloomfield and Charles Hockett get a bit more technical on this, referring to them as “special completive interjections” when used to answer a yes-no question. And maybe giving them a technical term is enough to get them under the interjection umbrella. But it still doesn’t feel quite right.

And thus I decide to dig deeper into this linguistic issue.

A Few More Options…

One possibility is that “Yes” and “No” are simply matters of convention. The Collins Dictionary goes for this option. Some linguists describe them as “function words” on this count. The idea is that we use them to express affirmation or negation as a matter of pragmatic usage, not literal meaning.

Linguist Henry Sweet, meanwhile, describes them as sentence words. The basic idea here, as best I understand it, is that certain words can function as complete sentences by themselves. And “Yes” and “No” are examples of this, functioning as sentences expressing affirmation and negation.

There’s also an element to which “Yes” and “No” seem to be contractions of older phrases. For instance, “yes” comes from the Old English gise, combining gea (meaning “yea”) and si (meaning “be it”). So “yes” is sort of like shorthand for saying “So be it”, which is a full sentence.

When we dig deep enough, then, there are plenty of ways to think about these words. And the best fit may depend on how they’re being used in specific cases or what aspect of the words you want to focus on. The big remaining question, I guess, is whether any of this matters in the slightest.

So, What Are “Yes” and “No” Anyway?

It turns out my initial confusion over these words was not unjustified. Even linguists can’t quite agree on how to classify them. Language is too messy to make that an easy task. And academics tend to like disagreeing with one another anyway, which complicates the endeavour further.

But what should we conclude?

I’d say “sentence adverb” is probably the simplest option, even if it involves accepting that adverbs can modify a sentence that hasn’t actually been spoken.

Likewise, there are certainly times when “Yes” and “No” are used as interjections.

Ultimately, though, the main takeaway is that it’s a largely academic matter. This isn’t to imply it’s unimportant: trying to understand how language works (and how people use it) is a valuable field of inquiry. It’s certainly one I find fascinating.

But, in this case at least, it’s hard to imagine it has much practical consequence.

All native English speakers know how to use these words in a variety of situations. And this is something we pick up from being part of a community of language users. So knowing what a “sentence adverb” or a “special completive interjection” is doesn’t make a jot of difference in practice.

The other takeaway is that I am a massive nerd. But you probably guessed that.