darken
v. 變黑暗；使黑暗；使不易了解→dark a.黑暗的

heighten
v. 提高，增高；增強，增加→height n.高，高度

lengthen
v. 使長；加長；變長→length n.長度

sharpen
v. 使銳利；使敏銳→sharp a.銳利的，敏銳的

chicken
n. 小雞→chicken-hearted a.膽小的→-en , small

kitten
n. 小貓→kitty n.(兒語)小貓→-en, small

rotten
a. 腐爛的(decayed, spoiled)；臭的(foul-smelling)；
腐敗的(corrupt)；不健全的(unsound) →-en, to become

wooden
a. 木製的；愚鈍的→-en , made of

woolen
a. 羊毛製的；羊毛的→-en, made of