for example, i have an english blog hosted in canada, targetting canada. as canadian people also speaks french, i want to add my best articles in my blog in french too. how can i manage this with best seo terms? i was thinking on adding a category called french and then adding all the french posts there. is that the best way? how do search engines work with different languages in same site?
There are 2 possibilities. First Option: is to use local domain extensions example for French you can buy a .FR domain and publish all the French content there, if you would have German language in the future you could buy a .DE domain etc, this works very good with search engines and local search results. Second Option: is to publish it on the same site example /fr/index.php for French and /de/index.php for German etc, this also works well but you may experience some difficulties to come up in the local results for example Google.FR (when searched only for French sites) or Google.DE (when searched only for German sites).