Certificate of Specialisation of Swedish Language
Would you like me to tell you, after completing the courses in the Swedish language, I will obtain a certificate of specialization?
First point: as far as I know Duolingo offers a certificate of knowledge of the English language for a fee, but not one for Swedish. (https://englishtest.duolingo.com/)
Second point: You have posted this discussion in the English from Greek forum! In the future, make sure you post in the appropriate forum. You can move this post to the Swedish forum by editing it and selecting the forum from the drop down list. :)