Only in Mongolian 39
What this means for learners
Mongolian and Garo share 7 sounds — roughly 15% of Garo's inventory overlaps with Mongolian. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 19 sounds found only in Garo represent the greatest pronunciation challenge for Mongolian 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, Mongolian has 39 sounds not used in Garo. Native Garo speakers learning Mongolian 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.