What this means for learners
Turkmen and Turkish share 21 sounds — roughly 53% of Turkish's inventory overlaps with Turkmen. 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 Turkish represent the greatest pronunciation challenge for Turkmen 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, Turkmen has 16 sounds not used in Turkish. Native Turkish speakers learning Turkmen 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.