What this means for learners
Pashto and Rundi share 22 sounds — roughly 58% of Rundi's inventory overlaps with Pashto. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 7 sounds found only in Rundi represent the greatest pronunciation challenge for Pashto 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, Pashto has 16 sounds not used in Rundi. Native Rundi speakers learning Pashto 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.