黄ばんでいる
The paper is yellowed.
紙が黄ばんでいます
The paper is completely yellowed.
紙がすっかり黄ばんでいます
The paper of the old book is completely yellowed.
昔の本の紙がすっかり黄ばんでいます
The paper of the old book on the shelf is completely yellowed.
本棚の中の昔の本の紙がすっかり黄ばんでいます
The paper of the old book on the shelf is completely yellowed now.
今本棚の中の昔の本の紙がすっかり黄ばんでいます