OBJECTIVES: - To investigate difficulties encountered during linguistic validation of the HAES into nineteen languages; - to discover whether certain source items consistently posed problems across multiple target languages; - to evaluate solutions.  METHODS: - Collation of back translation reviews and developer reviews across nineteen languages; -identification of problematic words and phrases based on written discussion between lead translators, project managers and developer; - investigation of patterns across languages; - review of methods used to overcome difficulties.  RESULTS: Three principle issues were discovered and solutions found: (1) 52% of languages removed 'A.M.' and 'P.M.' due to use of the 24 hour clock. The 12 hour clock markers were replaced with a word, like 'Uhr' in German; a letter, like 'h' in French; or simply numbers. (2) Ten languages had issues with the concepts 'weekday' or 'weekend' as there is often no direct translation available. Various solutions were discussed, including day of the week and day between Monday and Friday.  It was agreed that 'weekdays' could be translated as 'working days', and 'weekends' as 'Saturdays and Sundays' while several languages preferred to use the English word. (3) 94% of languages struggled to find an equivalent for 'skipping'. Many English back translations showed 'hopping' or 'jumping'.  The motion of skipping was discussed with translators as moving along lightly, stepping from one foot to the other with a hop or bounce