IS “HUH” A WORD?

IS “HUH” A WORD? Even if “huh” is universal, is it a word—rather than an involuntary response like a sneeze, a grunt, or an expression of pain? The authors give great weight to the fact “huh” is learned just as other words are learned. They say: “In American English-speaking children, it is employed and responded to somewhat erratically at 2.5 years but perfectly at 5 years.”