This document discusses several linguistic concepts: - Phonetics is the study of speech sounds. Articulatory phonetics studies how sounds are made. Auditory phonetics deals with perceiving sounds through hearing. - Co-articulation refers to making one sound at the same time as the next sound. Assimilation occurs when aspects of one sound are taken on by another sound in a sequence. - Languages can contain many word-like elements within single forms, as seen in the Swahili example "Ni-ta-ku-penda." - Morphemes can be free (ordinary words) or functional (conjunctions, prepositions, etc.).