If you own a blog, forum, website, you should not misuse words since it makes your website look unprofessional, untrustworthy, and spammy, so people might not want to link to it, or be on your website.
Learn to not misuse words, use proper grammar and spelling, and write great articles for your website, and you have a better chance of getting organic traffic from visitors who use word of mouth, or link to your site from their website.
This colorful and informative infographic by Onlineschooling has 8 very good example of commonly misused words I see both on websites and in reality.
Source: Onlineschooling.net