日本語 Japanese Ask Questions Thread 5

If you have a question about the language, ask it and fellow 4channers might see it and answer it for you.

Japanese - Ask questions thread
http://dis.4chan.org/read/lang/1174719097/1-40

日語 Japanese Ask Questions Thread2 質問
http://dis.4chan.org/read/lang/1206158123/1-40

日本語 Japanese Ask Questions Thread 3
http://dis.4chan.org/read/lang/1267485093/1-40

日本語 Japanese Ask Questions Thread 4
http://dis.4chan.org/read/lang/1302350850/1-40

Is it bothering anyone else that the line between verbs and adjectives (and even nouns to a certain extent) is an incredibly fuzzy one?

Example:
この本は汚れている
この本は汚いです