Zoho CRM's language support has developed beyond a single flat list of supported languages. It now distinguishes between languages that are fully translated and languages where only part of the interface is translated.
For fully supported languages, every system entity, module names, field labels, related lists, subform labels, picklist values, and any manually translated custom entities, displays in your chosen language. Fully supported languages currently include Arabic, Bahasa Indonesia, Bulgarian, Chinese (Simplified and Traditional), Croatian, Czech, Danish, Dutch, English (UK and US), French, German, Hebrew, Hindi, Hungarian, Italian, Japanese, Korean, Polish, Portuguese (Brazil and Portugal), Russian, Spanish, Swedish, Thai, Turkish, and Vietnamese.
For partially supported languages, only certain interface elements, such as module names, field labels, related list labels, subform labels, and picklist values, are translated. Setup page components, default buttons, and other system entities remain in a default fallback language rather than your selected one. Zoho maintains a longer, changing list of these partially supported languages, so if your business needs a language beyond the fully supported list, it's worth checking Zoho's current documentation to see exactly which parts of the interface will and won't translate.