Quote Originally Posted by kamka
polish has 7 cases. actually id dare to say most of the slavic languages have cases.
Yes, except for Bulgarian and Macedonian. They have no cases. Another important difference - these 2 languages are the only ones among Slavic languages to have the notion of a definite article.

The 7th case is Vocative(?) used in addressing. Russian has only some attavisms of this form.

See the following examples of vocatives in Russian:

бог - боже (God) (quite common - Боже мой!- My God!)
отец - отче (Father) (used in prayers)

Vocative is quite common in Ukrainian - мамо, дiду, хлопче, etc.