What this means for learners
Pomo and Hakka Chinese share 12 sounds — roughly 26% of Hakka Chinese's inventory overlaps with Pomo. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 35 sounds found only in Hakka Chinese represent the greatest pronunciation challenge for Pomo 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, Pomo has 26 sounds not used in Hakka Chinese. Native Hakka Chinese speakers learning Pomo 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.