Four letter words--Change 0 to 1 letter to make a new word

[Prof.Pepperwinkle]

rust.

[Ignatz]

yurt.

[llikewise]

your.

[Ignatz]

hour.

[Prof.Pepperwinkle]

Hugo.

[llikewise]

Hugs.

[MissTake]

shag.

[llikewise]

sham.

[Prof.Pepperwinkle]

mash *

[MissTake]

mush

[Elendil_s_Heir]

lush

[llikewise]

bush.

[Prof.Pepperwinkle]

buss

[llikewise]

busy.

[Ignatz]

stub.

[Prof.Pepperwinkle]

Bast

[pjd]

Baps.

[Ignatz]

spam.

[llikewise]

palm.

[MissTake]

plan