Post Class for language

Just upgraded to 2.7 I have been reading around about the new post_class function. Would it be possible perhaps to set two different special classes and use them as ‘language’ tags? In other words, set certain posts with ‘Japanese’ and then create a separate main page with only those posts that have *only* the post class ‘Japanese’ attached (and vice versa with english only). I current use a complicated and cumbersome system of categories to split the languages on my journal, but I was wondering if this new function could let me do that?

Is it possible and if so how do I go about defining special classes?

Thanks in advance!

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