So, if i want to say: "the men are cooks" i will say "a ferfiak szakacsok"?
Chefs are the bosses of the cooks, aren't they? And 'chef's' Hungarian equivalent is 'séf'.
esteuer, did you skip the earlier lessons? In Hungarian, the verb "to be" is not expressed explicitly in 3rd person present tense (is/are).
No. In statements of identity ("X is Y" or "Y is X"), both the nouns X and Y are in the nominative.
That is true also in English and many other languages in addition to Hungarian.
(True, nowadays English says "It's me" instead of "It is I", but historically it was the second form that was used. And it can be argued that the "me" in "it's me" is not accusative but rather an emphatic form of the nominative "I", like the "moi" in French "c'est moi".)