English verb conjugation
COULD YAW

Regular verb: yaw - yawed - yawed

Affirmation

Simple form	V-ing form
I could yaw you could yaw he could yaw we could yaw you could yaw they could yaw	I could be yawing you could be yawing he could be yawing we could be yawing you could be yawing they could be yawing
Perfect	V-ing perfect
I could have yawed you could have yawed he could have yawed we could have yawed you could have yawed they could have yawed	I could have been yawing you could have been yawing he could have been yawing we could have been yawing you could have been yawing they could have been yawing

Negation

Simple form	V-ing form
I couldn't yaw you couldn't yaw he couldn't yaw we couldn't yaw you couldn't yaw they couldn't yaw	I couldn't be yawing you couldn't be yawing he couldn't be yawing we couldn't be yawing you couldn't be yawing they couldn't be yawing
Perfect	V-ing perfect
I couldn't have yawed you couldn't have yawed he couldn't have yawed we couldn't have yawed you couldn't have yawed they couldn't have yawed	I couldn't have been yawing you couldn't have been yawing he couldn't have been yawing we couldn't have been yawing you couldn't have been yawing they couldn't have been yawing

Interrogative form

Simple form	V-ing form
could I yaw? could you yaw? could he yaw? could we yaw? could you yaw? could they yaw?	could I be yawing? could you be yawing? could he be yawing? could we be yawing? could you be yawing? could they be yawing?
Perfect	V-ing perfect
could I have yawed? could you have yawed? could he have yawed? could we have yawed? could you have yawed? could they have yawed?	could I have been yawing? could you have been yawing? could he have been yawing? could we have been yawing? could you have been yawing? could they have been yawing?

Interro-negative form

Simple form	V-ing form
couldn't I yaw? couldn't you yaw? couldn't he yaw? couldn't we yaw? couldn't you yaw? couldn't they yaw?	couldn't I be yawing? couldn't you be yawing? couldn't he be yawing? couldn't we be yawing? couldn't you be yawing? couldn't they be yawing?
Perfect	V-ing perfect
couldn't I have yawed? couldn't you have yawed? couldn't he have yawed? couldn't we have yawed? couldn't you have yawed? couldn't they have yawed?	couldn't I have been yawing? couldn't you have been yawing? couldn't he have been yawing? couldn't we have been yawing? couldn't you have been yawing? couldn't they have been yawing?