English’s odd, meaningless “do.”
“Do”: The Helping Verb
As an ordinary verb or a light verb, English “do” has near-equivalents in other languages. But where English “do” really stands out is as a helping verb. Actually, the way English uses all its helping verbs is unusual among languages of the world, but even among languages that use helping verbs the way English does, English “do” is odd.
In English, helping verbs switch places with their subject in order to form questions, such as “Have you eaten?” and “Where are they going?” This so-called subject-auxiliary inversion also happens when we put a negative adverb at the beginning of the sentence. For example, I might say, “Never will I allow that to happen!”
According to the World Atlas of Language Structures, subject-verb inversion is mostly limited to languages originating in Europe, and the English version of that strategy, subject-auxiliary inversion, is rarer still.
English Demands Helping Verbs
The requirement for a helping verb is so strong in English that when we want to form a question out of a clause that doesn’t have one, we bring in a helping verb anyway. And what helping verb do we use? That’s right; it’s “do.” For example, take the sentence, “I finished writing my book.” There’s no helping verb in that sentence, so to turn it into a question, we supply the helping verb “did”: “Did you finish writing your book?” In Chapter 1 of his book Our Magnificent Bastard Tongue, linguist John McWhorter points out that English is the only one of the Germanic languages to do this.
“Do” in Negative Sentences
There are other things that “do” does that set it apart. In negative sentences, English again uses “do” in a way that other Germanic languages don’t. Like questions, negative sentences in English require a helping verb to come before the word “not,” and when there is no other helping verb to be had, it’s “do” once again that steps in. So instead of just putting “no” or “not” at the beginning or the end of a sentence as many other languages do, English uses “do not” or “don’t.”
“Do” for Emphasis
Aside from questions and negations, you can even use “do” in sentences just to show emphasis. So if your mother chastises you for not making your bed, you wouldn’t just say, “But I made my bed”; you’d say, “But I did make my bed.” As McWhorter notes, these are more things that hardly any other languages in the world do.