Many of the countries participating in the fifth EVS wave share one or more languages with other countries. This means that, for each language, a different version of the questionnaire is produced in every country in which it is spoken. This is necessary because of the cultural and linguistic differences between countries sharing a language, and because some questions have a country-specific formulation (for instance, when the name of the country is mentioned in a question). However, it is preferable for the comparability of the data collected that the same-language versions of the questionnaire are harmonized: the same concepts in the Master Questionnaire should be translated with identical or equivalent concepts in the different countries.

Countries speaking a shared language were proposed two alternative variations of the standard team approach, in order to maximize the harmonization between same-language versions of the questionnaire.

• One option is the cooperation approach. In this approach, two or more countries sharing a language cooperate in all the steps of the translation process. In total, two (or more) draft translations are produced and reviewed in a joint meeting between the national teams. The aim of this approach is to agree on a shared interpretation of the Master Questionnaire, but then each country can adapt the commonly agreed translation to its cultural and linguistic specificities.
•  The alternative to cooperation is the adaptation approach. In this option, one country independently translates the questionnaire, then the others use its final translation as a basis for their national versions.