Adjectives: -ed or -ing
I am interestED in the book. (The reader/person feels it-Kişi deneyimliyor)
The book is interestING. (The thing which causes/is the source of the emotion- Bahsedilen duyguya sebep olan şey kitap)
The children were tired (The children feel it.- Çocukların hissettiği durum)
The children were tiring (Another person talks about the emotion the children cause/Durumu yani yorgunluğu hisseden adam; hissettiren çocuklar)