The smallest functioning unit in the composition of words is morpheme.

The statement you've provided is indeed correct: the smallest functioning unit in the composition of words is the morpheme. A morpheme is defined as the smallest unit of language that carries meaning and can stand alone or be combined with other morphemes to form words356710。It can be a word in itself, such as "place" or "an," or it can be a part of a word, like the prefix "re-" or the suffix "-ed" in the word "reappeared"6。Morphemes are the building blocks of words and are essential for understanding the structure and composition of language12489。