Favourite CLI tool: translate-shell
I usually do not recommend propriatery platforms but unfortunatelly in the category of machine translation programs there is no free (as in speech) alternative to proprietary platforms, such as Google's, Microsoft's, or DeepL's. Those who travel often, and who are not skillful in several world's languages, the machine translation services represents something that really improves their powers in finding their way in a foreign country.
$ wget git.io/trans $ chmod +x ./trans