English verb conjugation
COULD YADA-YADA

Regular verb: yada-yada - yada-yadaed - yada-yadaed

Affirmation

Simple form	V-ing form
I could yada-yada you could yada-yada he could yada-yada we could yada-yada you could yada-yada they could yada-yada	I could be yada-yadaing you could be yada-yadaing he could be yada-yadaing we could be yada-yadaing you could be yada-yadaing they could be yada-yadaing
Perfect	V-ing perfect
I could have yada-yadaed you could have yada-yadaed he could have yada-yadaed we could have yada-yadaed you could have yada-yadaed they could have yada-yadaed	I could have been yada-yadaing you could have been yada-yadaing he could have been yada-yadaing we could have been yada-yadaing you could have been yada-yadaing they could have been yada-yadaing

Negation

Simple form	V-ing form
I couldn't yada-yada you couldn't yada-yada he couldn't yada-yada we couldn't yada-yada you couldn't yada-yada they couldn't yada-yada	I couldn't be yada-yadaing you couldn't be yada-yadaing he couldn't be yada-yadaing we couldn't be yada-yadaing you couldn't be yada-yadaing they couldn't be yada-yadaing
Perfect	V-ing perfect
I couldn't have yada-yadaed you couldn't have yada-yadaed he couldn't have yada-yadaed we couldn't have yada-yadaed you couldn't have yada-yadaed they couldn't have yada-yadaed	I couldn't have been yada-yadaing you couldn't have been yada-yadaing he couldn't have been yada-yadaing we couldn't have been yada-yadaing you couldn't have been yada-yadaing they couldn't have been yada-yadaing

Interrogative form

Simple form	V-ing form
could I yada-yada? could you yada-yada? could he yada-yada? could we yada-yada? could you yada-yada? could they yada-yada?	could I be yada-yadaing? could you be yada-yadaing? could he be yada-yadaing? could we be yada-yadaing? could you be yada-yadaing? could they be yada-yadaing?
Perfect	V-ing perfect
could I have yada-yadaed? could you have yada-yadaed? could he have yada-yadaed? could we have yada-yadaed? could you have yada-yadaed? could they have yada-yadaed?	could I have been yada-yadaing? could you have been yada-yadaing? could he have been yada-yadaing? could we have been yada-yadaing? could you have been yada-yadaing? could they have been yada-yadaing?

Interro-negative form

Simple form	V-ing form
couldn't I yada-yada? couldn't you yada-yada? couldn't he yada-yada? couldn't we yada-yada? couldn't you yada-yada? couldn't they yada-yada?	couldn't I be yada-yadaing? couldn't you be yada-yadaing? couldn't he be yada-yadaing? couldn't we be yada-yadaing? couldn't you be yada-yadaing? couldn't they be yada-yadaing?
Perfect	V-ing perfect
couldn't I have yada-yadaed? couldn't you have yada-yadaed? couldn't he have yada-yadaed? couldn't we have yada-yadaed? couldn't you have yada-yadaed? couldn't they have yada-yadaed?	couldn't I have been yada-yadaing? couldn't you have been yada-yadaing? couldn't he have been yada-yadaing? couldn't we have been yada-yadaing? couldn't you have been yada-yadaing? couldn't they have been yada-yadaing?