English verb conjugation
CAN REQUIRE

Regular verb: require - required - required

Affirmation

Simple form	V-ing form
I can require you can require he can require we can require you can require they can require	I can be requiring you can be requiring he can be requiring we can be requiring you can be requiring they can be requiring
Perfect	V-ing perfect
I can have required you can have required he can have required we can have required you can have required they can have required	I can have been requiring you can have been requiring he can have been requiring we can have been requiring you can have been requiring they can have been requiring

Negation

Simple form	V-ing form
I can't require you can't require he can't require we can't require you can't require they can't require	I can't be requiring you can't be requiring he can't be requiring we can't be requiring you can't be requiring they can't be requiring
Perfect	V-ing perfect
I can't have required you can't have required he can't have required we can't have required you can't have required they can't have required	I can't have been requiring you can't have been requiring he can't have been requiring we can't have been requiring you can't have been requiring they can't have been requiring

Interrogative form

Simple form	V-ing form
can I require? can you require? can he require? can we require? can you require? can they require?	can I be requiring? can you be requiring? can he be requiring? can we be requiring? can you be requiring? can they be requiring?
Perfect	V-ing perfect
can I have required? can you have required? can he have required? can we have required? can you have required? can they have required?	can I have been requiring? can you have been requiring? can he have been requiring? can we have been requiring? can you have been requiring? can they have been requiring?

Interro-negative form

Simple form	V-ing form
can't I require? can't you require? can't he require? can't we require? can't you require? can't they require?	can't I be requiring? can't you be requiring? can't he be requiring? can't we be requiring? can't you be requiring? can't they be requiring?
Perfect	V-ing perfect
can't I have required? can't you have required? can't he have required? can't we have required? can't you have required? can't they have required?	can't I have been requiring? can't you have been requiring? can't he have been requiring? can't we have been requiring? can't you have been requiring? can't they have been requiring?