Multisite but on same domain

I want to create a new site with Expression Engine which has different languages. All the proposed solutions about having a new field for each language will not work here, that may work for a small site but I actually need each language site to be a different which means content can also be different.

I have decided that using the multi site manager is the probably the best way to go and to threat each language as a different website for a cleaner organization which is also able to scale.

They all will of course reside in the same EE install and server but my question is if I really have to use a different domain or sub-domain for this. I do have a different domain for each language, but there are strong reasons why I don’t want to use them.

I want to point all of them to the main domain and use a cookie or browser/geo detection to send the user to its own language if its a visitor or as a user to use his member setting.

I tried the sub-domain approach in the past and there are problems with that. First, using a sub-domain does not make sense for future planning since you can’t move this to another server, multi site works only in the same database, so the reason to use them makes no sense. Using a different domain means links will be different which I don’t want. There is also certificates problems if I use subdomains or different domains. Since we use a EV SSL it would be expensive to have to license one for each different domain or sub-domain.

Its not only the certificate and link issues, but there are also some central platforms in the main domain which already work in different languages, which means the domain does not actually change, just the language selection.

My question is if its still possible to use Multi Site and make EE think they are different sites?

Something like www.domain.com/en

For example could work. Reading the documentation its either sub-domain or a different domain. To resume I need to run 3 sites on the same domain. I need all of them to have its own templates files and template groups.

Is this possible?