a type of simple grammar displayed in the early stages of language development (especially the two-word stage). Pivot grammar is characterized by two-word utterances in which one word (the pivot word) is typically a function word, such as a determiner or preposition, and the other (the open word) is a content word, such as a noun or verb. A small child has relatively few pivot words in his or her vocabulary but uses them often and always in the same position relative to the open word. Open words are used less frequently, but the child learns more of them and can use them anywhere in a phrase. More juice, light off, and all gone are typical examples of pivot grammar: More, off, and all are pivot words; juice, light, and gone are open words.