Hey, Chino! I think you're referring to gender. Der die das, right? There are a few rules. For instance, words ending in -chen or -lein are always neutral, those ending in -heit or -ung are always feminine, etc. But mostly I think it's rote memorization and reading a lot so that the gender of familiar words comes easily.

Or perhaps in your entry you were referring to case. As in: "I think it's hard to memorize the case endings for German nouns/adjectives." But then you say that there are no rules, and there are definitely rules for those, so that's why I suggested "gender." Good luck on your exam!

hi chino,
maybe it would help you to Look more analytical
at grammar, so à Bit of Latin could give you more
help in understanding Konjugationen and
Deklinationen.
good luck
Blue

When Chino says "part of speech" I think she means whether the word is a noun, a verb, an adjective, an adverb, and so on.

Chino, 你的意思是不是：“这个词是名词，动词，形容词，副词，等等。”

Hello LaoBai! And it is precisely because I know a bit of German that I doubt "part of speech" is what she means, because German has very clear, consistent rules concerning parts of speech: Nouns are always capitalized, adjectives and nouns are declined according to case, etc. On the other hand, there are not really many rules for a given noun's gender, which is important because it determines its declension as well as the declension of surrounding adjectives. :)

Maybe you are right Sprachjunge. I'm glad I am not learning German because it would be too difficult for me.

Hey Sprachjunge, Blue and Laobai, thank you:D I was referring to the gender of German nouns, I'll try to find some rules:)

Hi Chino,
the genders of German nouns can be quite confusing, I know that. There are, however, a few rules, e.g. the ones that Sprachjunge already mentioned. To find out more, you may find this site helpful:
http://german.about.com/library/weekly/aa042098.htm