Homebrew and Git - Wrong language on the command line
Recently, I've started to observe the same behavior, particularly with git (and after updating to MacOS Mojave). At first, I thought it's an issue with git itself. So, I've reinstalled git with homebrew to no avail. 

However, going to "Language &amp; Region" tab in the MacOS "Settings", and removing other languages from the list that you don't need (note: these are different from the keyboard input sources) resulted in git displaying the command output messages in terminal in the desired language (in my case, English).

Notably, this problem occurred to me only in the macOS terminal (and not, e.g., VSCode's terminal).