At the start of the COVID-19 pandemic, there was a challenge made to translate “wash your hands” into as many languages as possible on the Ethnologue website. The results of this project demonstrate some of the many differences that are found among languages, even for such a simple sentence.
Some of these differences may be minor. For example in many languages including Lefa (Cameroon), there is just one word meaning arm/hand. Thus you say “wash your arms/hands” – implying which portion is being washed.
Other languages may have different ways of referring to this body part. For example, in Gumuz (Ethiopia), you need to “classify” what you are talking about. Here you would use a particle that refers to larger body parts (as well as things seen as body-like including walls), as opposed to other classifiers, like for example “head” (used as well for extremities like fingers and toes). So you have “wash-you-‘body’ arm/hand.” Here, too, there is no distinction between arm and hand, and plural (although possible) is usually implied.
In Kankanaey (Philippines), there is a single, non-dividable verb bo which means 'wash hands'.
But sometimes, besides these relatively straight-forward grammatical differences, there are other factors that come into play. For example, in Bura (Nigeria) you would say “let us wash hand”. Here we have the implied plural we have seen before, and no possessive pronoun. But, although Bura has an imperative, it is not used here. That would be rude when potentially talking to people older or more respected that you (as in a community service announcement).
Finally, sometimes you have problems if you don’t pay attention to the details of the situation. The proposal for translation in Akoose (Cameroon) was “hands you should suck/lick”. This is culturally appropriate when “washing hands” refers to preparing to eat, but quite counter-productive for stopping the spread of a virus!
(Note: this entire discussion comes from comments from linguists in a discussion list related to entries in the project that they knew well -- an actual in depth study of all the results would likely give even more interesting differences).