ought to knife
Regular verb: knife - knifed- knifed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I ought to knife
you ought to knife
he ought to knife
we ought to knife
you ought to knife
they ought to knife 	I ought to be knifing
you ought to be knifing
he ought to be knifing
we ought to be knifing
you ought to be knifing
they ought to be knifing	I ought to have knifed
you ought to have knifed
he ought to have knifed
we ought to have knifed
you ought to have knifed
they ought to have knifed	I ought to have been knifing
you ought to have been knifing
he ought to have been knifing
we ought to have been knifing
you ought to have been knifing
they ought to have been knifing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I ought not to knife
you ought not to knife
he ought not to knife
we ought not to knife
you ought not to knife
they ought not to knife 	I ought not to knifing
you ought not to knifing
he ought not to knifing
we ought not to knifing
you ought not to knifing
they ought not to knifing	I ought not to have knifed
you ought not to have knifed
he ought not to have knifed
we ought not to have knifed
you ought not to have knifed
they ought not to have knifed	I ought not to have been knifing
you ought not to have been knifing
he ought not to have been knifing
we ought not to have been knifing
you ought not to have been knifing
they ought not to have been knifing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
ought to I knife?
ought to you knife?
ought to he knife?
ought to we knife?
ought to you knife?
ought to they knife? 	ought to I be knifing?
ought to you be knifing?
ought to he be knifing?
ought to we be knifing?
ought to you be knifing?
ought to they be knifing? 	ought to I have knifed?
ought to you have knifed?
ought to he have knifed?
ought to we have knifed?
ought to you have knifed?
ought to they have knifed? 	ought to I have been knifing?
ought to you have been knifing?
ought to he have been knifing?
ought to we have been knifing?
ought to you have been knifing?
ought to they have been knifing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
ought I not to knife?
ought you not to knife?
ought he not to knife?
ought we not to knife?
ought you not to knife?
ought they not to knife? 	ought I not to be knifing?
ought you not to be knifing?
ought he not to be knifing?
ought we not to be knifing?
ought you not to be knifing?
ought they not to be knifing? 	ought I not to have knifed?
ought you not to have knifed?
ought he not to have knifed?
ought we not to have knifed?
ought you not to have knifed?
ought they not to have knifed? 	ought I not to have been knifing?
ought you not to have been knifing?
ought he not to have been knifing?
ought we not to have been knifing?
ought you not to have been knifing?
ought they not to have been knifing?