English verb conjugation
COULD AD-LIB

Regular verb: ad-lib - ad-libed - ad-libed

Affirmation

Simple form	V-ing form
I could ad-lib you could ad-lib he could ad-lib we could ad-lib you could ad-lib they could ad-lib	I could be ad-libing you could be ad-libing he could be ad-libing we could be ad-libing you could be ad-libing they could be ad-libing
Perfect	V-ing perfect
I could have ad-libed you could have ad-libed he could have ad-libed we could have ad-libed you could have ad-libed they could have ad-libed	I could have been ad-libing you could have been ad-libing he could have been ad-libing we could have been ad-libing you could have been ad-libing they could have been ad-libing

Negation

Simple form	V-ing form
I couldn't ad-lib you couldn't ad-lib he couldn't ad-lib we couldn't ad-lib you couldn't ad-lib they couldn't ad-lib	I couldn't be ad-libing you couldn't be ad-libing he couldn't be ad-libing we couldn't be ad-libing you couldn't be ad-libing they couldn't be ad-libing
Perfect	V-ing perfect
I couldn't have ad-libed you couldn't have ad-libed he couldn't have ad-libed we couldn't have ad-libed you couldn't have ad-libed they couldn't have ad-libed	I couldn't have been ad-libing you couldn't have been ad-libing he couldn't have been ad-libing we couldn't have been ad-libing you couldn't have been ad-libing they couldn't have been ad-libing

Interrogative form

Simple form	V-ing form
could I ad-lib? could you ad-lib? could he ad-lib? could we ad-lib? could you ad-lib? could they ad-lib?	could I be ad-libing? could you be ad-libing? could he be ad-libing? could we be ad-libing? could you be ad-libing? could they be ad-libing?
Perfect	V-ing perfect
could I have ad-libed? could you have ad-libed? could he have ad-libed? could we have ad-libed? could you have ad-libed? could they have ad-libed?	could I have been ad-libing? could you have been ad-libing? could he have been ad-libing? could we have been ad-libing? could you have been ad-libing? could they have been ad-libing?

Interro-negative form

Simple form	V-ing form
couldn't I ad-lib? couldn't you ad-lib? couldn't he ad-lib? couldn't we ad-lib? couldn't you ad-lib? couldn't they ad-lib?	couldn't I be ad-libing? couldn't you be ad-libing? couldn't he be ad-libing? couldn't we be ad-libing? couldn't you be ad-libing? couldn't they be ad-libing?
Perfect	V-ing perfect
couldn't I have ad-libed? couldn't you have ad-libed? couldn't he have ad-libed? couldn't we have ad-libed? couldn't you have ad-libed? couldn't they have ad-libed?	couldn't I have been ad-libing? couldn't you have been ad-libing? couldn't he have been ad-libing? couldn't we have been ad-libing? couldn't you have been ad-libing? couldn't they have been ad-libing?