What this means for learners
Kpelle and Fɔn share 26 sounds — roughly 53% of Fɔn's inventory overlaps with Kpelle. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 16 sounds found only in Fɔn represent the greatest pronunciation challenge for Kpelle speakers. The adult brain tends to map unfamiliar sounds onto the closest native equivalent — a process that produces the characteristic "accent" of a second-language speaker. Learning to hear and produce these sounds as distinct requires focused ear training, not just repetition.
Conversely, Kpelle has 23 sounds not used in Fɔn. Native Fɔn speakers learning Kpelle will face the mirror-image challenge with these sounds.
Phoneme inventories from PHOIBLE. Data reflects one documented inventory per language; some variation exists across dialects and sources.