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

beat :heart:

tabs.

Taos :cactus:

stop.

post :mailbox:

spit.

tips.

this.

hiss.

ship.

fish!

fist.

fast :racing_car:

fest.

stem.

mast :sailboat:

math :abacus:

myth.

moth.

them.