Why Tone Carries Meaning
An analysis of the Yorùbá three-level register tone system, demonstrating through minimal pairs and grammatical operations why tone is an essential phonemic component rather than optional decoration.
The idea
Yorùbá is a register tone language in which pitch functions as an indispensable property of every syllable. Differences in pitch distinguish entirely unrelated lexical entries that otherwise share the same consonants and vowels, and shifts in tone execute core grammatical operations such as tense marking, predication, and genitive association [S1, S8]. Stripping tone marks from written Yorùbá does not remove minor pronunciation guides: it collapses distinct words into ambiguous strings and strips the morphosyntactic framework of the language. This file sets out the phonological architecture of the Yorùbá tonal system, documents its lexical function through minimal sets across monosyllabic verbs and disyllabic nouns, examines its role in sentence-level grammar, and reviews the linguistic debates surrounding tonal representation and computational diacritic restoration.