It is quite easy to add multiple language keyboards to a computer, however now that I've become fluent in another language, and use it quite often, I've gotten tired of seeing the red underline (meaning you've spelled a word wrong) everytime I write messages or emails in another language. Does anyone know how to set a computer up to understand two languages, or have two languages, if this question makes sense, maybe I'm describing the problem poorly, but it makes sense in my head.
Simplified, Sparknotes: Want to have different languages understood on my computer, avoiding the red underline, and having spell check for another language.