overall model /db design comments sought

Hi there,

Im wondering how to best go about this and would appreciate some general
pointers etc.

Background:
just a language learning site where users can can write posts both in
their native language and the language they are learning.
Users can view all the posts that are in their native language or the
ones in the langauge they are learning.

I know i need a user and post models but do I also need a language one?

A user has many posts and a post belongs to a language
A language has many posts
is that right?

Should i be creating a relationhip between the language model and the
user?
A user has a *native* language
A user has a *foreign* language

It doesnt sound right to me plus i dont even know how I could
technically set that up as thats two "has a" to the same language model.

Instead I thought in my user objects Ill have two attributes, native
language and foreign languge. When they write a post theyll specify if
its in their native or foreign language. Then Controller->post>create
will take that option and do something like

@sentence = @user.post.build(params[:post])

How is the above app design???

Should i be creating a relationhip between the language model and the
user?
A user has a *native* language
A user has a *foreign* language

Hmm... could be a model question right there?

Users can have many foreign tongues (if I speak perhaps English, French,
German and Russian)

Arguably, users can have multiple 'native' tongues... it depends on
their frequency of usage I think.

So perhaps the distinction between native and foreign is a question of
command of a particular language, which you could measure in some
gradient (1 = Just learning, 10 = Expert) that the user would choose if
you wanted users to be able to self-qualify their expertise.