Attention to detail matters. On a website, bad grammar has been shown to reduce sales. But more often it seems that bad grammar accumulates subconsciously and results in less trust for the site.

BJ Fogg has said that web credibility is about making your website in such a way that it comes across as trustworthy and competent. Your website is often the first point of contact for the customers, responsible for first impressions and revenue.

Typos and grammatical errors are either immediately recognized and turn off readers, or they are subtle and slowly damage credibility throughout the copy.

Just fix these errors.