Do-support is a specific linguistic term for a phenomenon in English grammar where speakers or writers have to include the verb “do” as an auxiliary verb. This happens with questions, which are also called interrogative clauses, as well as negative statements or responses. Understanding how this do-support is used is an important part of language learning for those who are studying English.
The characteristic feature of do-support is that the phrase takes on an additional verb, which is often called a “helping” verb. For example, the simple positive statement, “I want to go,” includes only one verb, “want.” When the speaker or writer changes the statement to a negative statement, it takes on an additional verb, as in the phrase “I do not want to go.”
With the above example, the question form also adds do-support, where the question would be phrased, “do you want to go"? Here, the verbs “do” and “go” are at separate ends of the sentence, which may be confusing for some language learners. The key idea is to identify the additional “do” verb, and be able to understand its use in the language.
Do-support is just one example of complexities in the English language that create problems for straightforward syntax modeling. A program or person who is doing syntax modeling for English might phrase the sentence, “John does not want a car,” as either, “John not want a car,” or, “John wants a car not.” The syntax of these phrases is insufficient to actually express the idea in a negative way.
Instructors or linguists may present do-support in many different ways. This idea might be called by various names, or just demonstrated through modeling of interrogatives, positives, and negatives in sequence. By modeling question, positive, and negative forms of the same sentences, it becomes clear that two of these forms have the additional “do” verb in different forms, according to the subject.
In general, understanding do-support will help English-language learners understand the broader uses of auxiliary verbs. For example, the verb “be” in various forms is also used similarly in questions and negative responses. Learning about do-support can go along with learning about common sentence structures for various English verb tenses, where learners may combine the successful use of the auxiliary verb with the successful alteration of verbs to present, past, or future tenses.