Hi I'm an italian SEO and this is my first thread in DP. My english isn't very good but i'll try to write what i think about Google & languages. Many SEOs already knows that a link didn't give only a boost to a website, but it can also give to Google some informations about the site. The most famous infomation is the topic, but pheraps the most important one is the language. A link can change a bit the language of the page linked, so if you link an italian page from many english websites it's possible to change radically the language of the italian page and google will think that the page isn't italian but english. The consequence is a decrease of the italian page ranking in italian SE (google.it google.ch), but at the same time your ranking will increase in the other SE. Have you ever experienced this kind of "penalty"?
I've struggled with this question also. It seems to me that the language is not the most important factor, but where the website(s) you getting linked from are hosted. One site I have ranks number 1 in google.com but in google.nl I'm getting stuck at #8. This site gets a lot of links from usa hosted websites. So I think that's the reason why it's #1 in .com. This site does'nt have as much links coming from websites hosted in my country so it's stuk at number 8. I hope I make soms sense here.
Yes but in my opinion the language definition is: 1) text (structure and lexic) 2) links (inBound & outBound) 3) geolocation of the server 4) (and maybe some else) ... Probably google has defined a language through some rule (a little vocabulary, structure, etc..), but now he his expanding is knowledge through links and geolocation. However i think that links can influence language more than geolocation.