Google does not know the language tags ?

I do not know a blog (Indonesia Furniture Handicraft Wholesale Marketplace ) already using meta tags in English Language but has no effect for google that blogs are in English. Yet the article also spoke English, but google says it speak Indonesian. It is strange, and I do not know how to google increasingly recognize the language of a weblog.

Something like this certainly not fun because my weblog target is to use the English language which should be good for google.com. With reality like this certainly makes me difficult to achieve good position on SERP (search engine result page) google.com.

I think it possible that google currently does not use the language meta tag? If not what and how to explain to google that article I use English? If based on the geographical course I do not think so, because the server I was in America but in fact, in recognizable using the Indonesian language.

My estimate of what might be the language of a blog influenced by the language used in the main domain so that every blog that uses sub domains always follow the main domain. Of course that with the exception of his own blogspot which is different, including in terms of alexa.