In this post Forrester takes a firm stance against poor spelling and grammar, explicitly stating it has an impact on search rankings. This is a stance Google has never taken, or at least they have never expressed their position on spelling and grammar as clearly as Bing has.
Google has their Panda algorithm in place that weeds out poor quality content and allows the good quality content to rank higher, but when judging quality content it’s unclear to what extent spelling and grammar comes into play.
It has been suggested by Matt Cutts, even as recently as this month, that site owners should be mindful of spelling and grammar when it comes to the content they publish. However, he has never stated that Google takes action against pages that routinely publish content with spelling and grammar errors.
Forrester explains Bing is judged by the quality of the results they show so they are constantly keeping an eye on the quality of content that ranks well, which includes looking at spelling and grammar. However, he is also empathetic to the fact that occasionally content with errors slips past the editors. It happens to everyone.
It doesn’t look like Bing intends to penalize those rare instances of content being published on a site that has a history of being relatively error-free, they’re more concerned with penalizing sites that routinely publish content with spelling and grammar errors.
This stance against poor spelling and grammar is an admirable move by Bing, I can’t help but wonder if Google will release a similar statement.
http://www.searchenginejournal.com/bing-takes-stance-poor-spelling-grammar-saying-will-hurt-rankings/92061/