When taking the survey, if the requester is signed into ServiceDesk Plus MSP Cloud with their credentials, the display language of survey will be set according to the requester's preferred language in their Zoho Accounts user profile. 

When the requester is not signed into the application,

For SDP Survey, the display language is based on the requester's browser settings .

For Zoho Survey, the survey is displayed in the default language of the Zoho Survey account. If SDAdmins enable language translation, users can select a preferred language.