How to make language versions of the site for a good site?

Question

Search Engine Optimization

There is an old trust corporate site (tits 200 pr 5 dmoz YAK) well pumped for complex high-frequency requests in some regions. Topic - web & mobile development.
The site is in YaK - different regions are assigned to it: Moscow, Minsk, St. Petersburg ...
There was a need to have a full-fledged English and German version of the project to promote services to Germany and the USA.
The site has 150-200 pages. The same will be true in foreign countries.
How would it be more correct to organize multilingualism:
- folders /en/ /de/
- subdomains en.sitename.com, de.sitename.com
- new domains sitename.de, sitename.com
PS I read a lot on the net - I did not understand anything for myself .. opinions differ. Maybe someone will advise something in my particular situation.

Answer 1

- folders /en/ /de/ IMHO

Answer 2

And what are the arguments about this ... And what to do in this case with the title - a redirect to geo or whatever you think. The head has already been broken ... for a week the task has been standing still.