Can anyone explain to me what does the sufix ....ýn added do a noun do?

For example "Oðlan masanýn altýnda" .  I don´t know why Rosetta Stone suppose to be such a wonderful program because it does not explain anything, it´s just repetition.

In the above example -in is a suffix that indicates the noun is in gentive case. Genitive case is used to indicate a possessive relationship (kind of like ´s in English). To form a possessive relationship you´d add -in (according to vowel harmony) to the possessor and the possessed noun is going to be suffixed 3rd person possessive ending (- (s)i, -lari).

Some examples may be: man´s house - adamýn evi, girl´s ball - kýzýn topu, Ahmet´s car - Ahmet´in arabasý

The construction is used a lot in spacial relationship, just as in your example:

masanin altinda

masa - n - ýn alt - Ã½ - n - da

- masa = table

- alt = bottom

n is used as a buffer letter (see Doudi´s post on that, it explains what buffer letters are used where)

da means in or at

so the possessive construction is masanýn altý - the bottom of the table, or the underneath of the table - with "da" it translates to "under the table"

The suffix -in may also mean "your" when added to the noun that ends in a consonant - for example ev (house) - evin (your house), muz (banana) - muzun (your banana), ad (name) - adýn (your name).

Here´s a link to a site where you can find more info on possessive relationships:

http://web.archive.org/web/20071225095015/www.turkishlanguage.co.uk/possessiverelationship.htm

and I´m sure if you search the classes here, you´ll find a lesson or two on it as well.

Thanks, I think I got it now.