I've installed wordpress on the domain and I am gonna give a second language so I have also installed another wordpress inside a subdirectory. Now it's situated in:

mysite.com/en/wordpress

however i need so that it is

mysite.com/en

For that first installation i adopted this informative guide:

http://codex.wordpress.org/Giving_WordPress_Its_Own_Directory

However it appears enjoy it does not use multisites.... So I fix this?

Thanks ahead of time!

No it's really no problem to alter it. A couple of steps to follow along with.

Get into your WordPress admin panel increase the website url and blog url to suggest for your new location. Then click save.

Relabel the folder from wordpress to en

Finally you might have some issues with images, if that's the case you will have to replace that old web addresses inside your database. Personally I'd import the database, operate a find and replace after which re-import the sql script.

Here's another solution though that runs a question around the database as well as work. http://www.master-script.com/moving-wordpress-site-to-new-domain.html

Note if you are planning to operate the find and replace around the database anyway the initial step does not matter as it will likely be transformed also.