As account admin, got to the Account page and click Account Languages.
Set up multilanguage support
Set up multilanguage sending and signing
All Adobe Acrobat Sign service plans let both senders and signers select their choice from 34 available languages, including English, German, Chinese, Japanese, Korean, French, Spanish, Italian, Dutch, and more. The enterprise service plan also lets senders request signatures in any of these languages.
To change the default language of the web application, for users in your account, select a language from the drop-down list under Account Language Preference. You can also either allow or deny users access to change the language by selecting this option.
To change the language of the signing experience for your signers, select the desired language from the drop-down list under Signing Language. You can allow or deny signers the ability to change the language of the signing experience by selecting this option.