SpellcheckLanguage

Force-enables spellcheck languages. Unrecognized languages in the list will be ignored. If you enable this policy, spellcheck will be enabled for the languages specified, in addition to the languages for which the user has enabled spellcheck. If you do not set this policy, or disable it, there will be no change to the user's spellcheck preferences. If the SpellcheckEnabled policy is set to false, this policy will have no effect. If a language is included in both this policy and the SpellcheckLanguageBlocklist policy, this policy is prioritized and the spellcheck language is enabled. The currently supported languages are: af, bg, ca, cs, da, de, el, en-AU, en-CA, en-GB, en-US, es, es-419, es-AR, es-ES, es-MX, es-US, et, fa, fo, fr, he, hi, hr, hu, id, it, ko, lt, lv, nb, nl, pl, pt-BR, pt-PT, ro, ru, sh, sk, sl, sq, sr, sv, ta, tg, tr, uk, vi.