David Harry, aka TheGypsy, has interpreted yet another series of Google patents that give insight into international and local search results.
There are three patents he mentions, starting with one about “ordering of search results based on language and/or country of the search results” which starts with regular search ranking and then looks at language and reorders and does so again when country is factored in where possible.
The other patents suggests there is regional consideration employed within that subset, and usage of language by known or recognized country or region’s use of langauge.
These applications show possible approaches and are well detailed by Harry.