The immediate constituents?

The immediate constituents refer to the smallest units of a linguistic structure that cannot be further divided without losing their meaning or grammatical function. In other words, they are the basic building blocks of a sentence or phrase. For example, in the sentence "The cat is sleeping," the immediate constituents are "the," "cat," "is," and "sleeping." These words cannot be broken down any further without losing their individual meanings or grammatical functions within the sentence.