My mother tongue is Portuguese, I live in a French speaking area and I produce English documents at work. Can you imagine how it feels to try to keep track of three languages at once?
My laptops reflect my reality and each software is setup in a different language, which makes it a hard job to grammar check my texts.
To ensure the quality of my writing (specially in the office), I researched and found a nice tool for revising texts.
SpellCheck.net is a free online tool and, despite its amateur looks, it works very well, specially when it comes to spelling mistakes and typos.
If you use English at work too, I recommend it.