English verb conjugation
COULD TWINKLE

Regular verb: twinkle - twinkled - twinkled

Affirmation

Simple form	V-ing form
I could twinkle you could twinkle she could twinkle we could twinkle you could twinkle they could twinkle	I could be twinkling you could be twinkling she could be twinkling we could be twinkling you could be twinkling they could be twinkling
Perfect	V-ing perfect
I could have twinkled you could have twinkled she could have twinkled we could have twinkled you could have twinkled they could have twinkled	I could have been twinkling you could have been twinkling she could have been twinkling we could have been twinkling you could have been twinkling they could have been twinkling

Negation

Simple form	V-ing form
I could not twinkle you could not twinkle she could not twinkle we could not twinkle you could not twinkle they could not twinkle	I could not be twinkling you could not be twinkling she could not be twinkling we could not be twinkling you could not be twinkling they could not be twinkling
Perfect	V-ing perfect
I could not have twinkled you could not have twinkled she could not have twinkled we could not have twinkled you could not have twinkled they could not have twinkled	I could not have been twinkling you could not have been twinkling she could not have been twinkling we could not have been twinkling you could not have been twinkling they could not have been twinkling

Interrogative form

Simple form	V-ing form
could I twinkle? could you twinkle? could she twinkle? could we twinkle? could you twinkle? could they twinkle?	could I be twinkling? could you be twinkling? could she be twinkling? could we be twinkling? could you be twinkling? could they be twinkling?
Perfect	V-ing perfect
could I have twinkled? could you have twinkled? could she have twinkled? could we have twinkled? could you have twinkled? could they have twinkled?	could I have been twinkling? could you have been twinkling? could she have been twinkling? could we have been twinkling? could you have been twinkling? could they have been twinkling?

Interro-negative form

Simple form	V-ing form
could I not twinkle? could you not twinkle? could she not twinkle? could we not twinkle? could you not twinkle? could they not twinkle?	could I not be twinkling? could you not be twinkling? could she not be twinkling? could we not be twinkling? could you not be twinkling? could they not be twinkling?
Perfect	V-ing perfect
could I not have twinkled? could you not have twinkled? could she not have twinkled? could we not have twinkled? could you not have twinkled? could they not have twinkled?	could I not have been twinkling? could you not have been twinkling? could she not have been twinkling? could we not have been twinkling? could you not have been twinkling? could they not have been twinkling?