Since keywords and APIs are usually in English, continuing to follow that convention in your variable names is often the most natural option.
But in cases where the program will be dealing with some concept that doesn't exist in English, being able to refer to things by their actual name, in the native language (assuming that's also the native language of the customer and development team), is much better than inventing a confusing and unnatural English translation.
But in cases where the program will be dealing with some concept that doesn't exist in English, being able to refer to things by their actual name, in the native language (assuming that's also the native language of the customer and development team), is much better than inventing a confusing and unnatural English translation.