I've heard of a lot of opinions from various SEO specialists about what keyword density is required and how to calculate it. My thinking is that you just write naturally, and spontaneously, without thinking about SEO and keywords. If the keyword happens to come in sentences, it should not really matter. I mean, in an SEO forum, SEO will be written a lot of times on every page. So, do you stop saying SEO in an SEO forum?
Keyword Density 
Linear Mode
