How does Google determine the language of the site?

How to get a page listed in Google results for a certain language

[Jozef]

Hi,

How does Google determine what language is site/page written in?

One would think it is <META NAME="Language" CONTENT="xx">, but when I searched the web with option "Search pages written in: Xxxxxx", it showed also pages which do not use that tag.

I got a page in Slovak with translation into English. When I decided to use the tag on every page, traffic from Google decreased by 25%, but was still not listed under Slovak.

Any ideas?

Jozef

[John_Caius]

I have a page with no meta tags and content in both French and English. Google offers to translate it into English, translates the French reasonably well, but oddly also translates the correct English content into some weird form of Fringlish.

[heini]

Jozef, welcome to WebmasterWorld!

Google, like any other major search engine uses automatic language detection.
So in theory they are not dependant on the language meta tag.
In practice Google has several problems in this regard. It seems like it only really works with the major languages on the web, like french, spanish, english, russian etc.