mold vs work on

mold is a noun but work on is not a noun.

Word	Noun	Adjective	Verb	Adverb
mold	Yes	No	Yes	No
work on	No	No	Yes	No

mold (noun)	work on (noun)
container into which liquid is poured to create a given shape when it hardens
sculpture produced by molding
a distinctive nature, character, or type
a dish or dessert that is formed in or on a mold
a fungus that produces a superficial growth on various kinds of damp or decaying organic matter
the process of becoming mildewed
the distinctive form in which a thing is made
loose soil rich in organic matter

mold (verb)	work on (verb)
become moldy; spoil due to humidity	shape, form, or improve a material
shape or influence; give direction to	to exert effort in order to do, make, or perform something
fit tightly, follow the contours of
form by pouring (e.g., wax or hot metal) into a cast or mold
make something, usually for a specific function
form in clay, wax, etc