How do I track where the language is coming from? If I'm building a website, and I end up putting together plugins, I'd like to know where the foreign language is coming from?
When I'm testing my page, I'm getting Google Translate.
You can track the usage of Google Translate for websites by using Google Analytics which is very common for webmasters for tracking all types of usesful things.
Once you've setup Google Analytics head over to Event Tracking > Actions and there should be a row with translation actions.