English verb conjugation
CAN CURVE

Regular verb: curve - curved - curved

Affirmation

Simple form	V-ing form
I can curve you can curve he can curve we can curve you can curve they can curve	I can be curving you can be curving he can be curving we can be curving you can be curving they can be curving
Perfect	V-ing perfect
I can have curved you can have curved he can have curved we can have curved you can have curved they can have curved	I can have been curving you can have been curving he can have been curving we can have been curving you can have been curving they can have been curving

Negation

Simple form	V-ing form
I cannot curve you cannot curve he cannot curve we cannot curve you cannot curve they cannot curve	I cannot be curving you cannot be curving he cannot be curving we cannot be curving you cannot be curving they cannot be curving
Perfect	V-ing perfect
I cannot have curved you cannot have curved he cannot have curved we cannot have curved you cannot have curved they cannot have curved	I cannot have been curving you cannot have been curving he cannot have been curving we cannot have been curving you cannot have been curving they cannot have been curving

Interrogative form

Simple form	V-ing form
can I curve? can you curve? can he curve? can we curve? can you curve? can they curve?	can I be curving? can you be curving? can he be curving? can we be curving? can you be curving? can they be curving?
Perfect	V-ing perfect
can I have curved? can you have curved? can he have curved? can we have curved? can you have curved? can they have curved?	can I have been curving? can you have been curving? can he have been curving? can we have been curving? can you have been curving? can they have been curving?

Interro-negative form

Simple form	V-ing form
can I not curve? can you not curve? can he not curve? can we not curve? can you not curve? can they not curve?	can I not be curving? can you not be curving? can he not be curving? can we not be curving? can you not be curving? can they not be curving?
Perfect	V-ing perfect
can I not have curved? can you not have curved? can he not have curved? can we not have curved? can you not have curved? can they not have curved?	can I not have been curving? can you not have been curving? can he not have been curving? can we not have been curving? can you not have been curving? can they not have been curving?