English verb conjugation
COULD FIB

Regular verb: fib - fibbed - fibbed

Affirmation

Simple form	V-ing form
I could fib you could fib he could fib we could fib you could fib they could fib	I could be fibbing you could be fibbing he could be fibbing we could be fibbing you could be fibbing they could be fibbing
Perfect	V-ing perfect
I could have fibbed you could have fibbed he could have fibbed we could have fibbed you could have fibbed they could have fibbed	I could have been fibbing you could have been fibbing he could have been fibbing we could have been fibbing you could have been fibbing they could have been fibbing

Negation

Simple form	V-ing form
I couldn't fib you couldn't fib he couldn't fib we couldn't fib you couldn't fib they couldn't fib	I couldn't be fibbing you couldn't be fibbing he couldn't be fibbing we couldn't be fibbing you couldn't be fibbing they couldn't be fibbing
Perfect	V-ing perfect
I couldn't have fibbed you couldn't have fibbed he couldn't have fibbed we couldn't have fibbed you couldn't have fibbed they couldn't have fibbed	I couldn't have been fibbing you couldn't have been fibbing he couldn't have been fibbing we couldn't have been fibbing you couldn't have been fibbing they couldn't have been fibbing

Interrogative form

Simple form	V-ing form
could I fib? could you fib? could he fib? could we fib? could you fib? could they fib?	could I be fibbing? could you be fibbing? could he be fibbing? could we be fibbing? could you be fibbing? could they be fibbing?
Perfect	V-ing perfect
could I have fibbed? could you have fibbed? could he have fibbed? could we have fibbed? could you have fibbed? could they have fibbed?	could I have been fibbing? could you have been fibbing? could he have been fibbing? could we have been fibbing? could you have been fibbing? could they have been fibbing?

Interro-negative form

Simple form	V-ing form
couldn't I fib? couldn't you fib? couldn't he fib? couldn't we fib? couldn't you fib? couldn't they fib?	couldn't I be fibbing? couldn't you be fibbing? couldn't he be fibbing? couldn't we be fibbing? couldn't you be fibbing? couldn't they be fibbing?
Perfect	V-ing perfect
couldn't I have fibbed? couldn't you have fibbed? couldn't he have fibbed? couldn't we have fibbed? couldn't you have fibbed? couldn't they have fibbed?	couldn't I have been fibbing? couldn't you have been fibbing? couldn't he have been fibbing? couldn't we have been fibbing? couldn't you have been fibbing? couldn't they have been fibbing?