ought to flatten
Regular verb: flatten - flattened- flattened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I ought to flatten
you ought to flatten
she ought to flatten
we ought to flatten
you ought to flatten
they ought to flatten 	I ought to be flattening
you ought to be flattening
she ought to be flattening
we ought to be flattening
you ought to be flattening
they ought to be flattening	I ought to have flattened
you ought to have flattened
she ought to have flattened
we ought to have flattened
you ought to have flattened
they ought to have flattened	I ought to have been flattening
you ought to have been flattening
she ought to have been flattening
we ought to have been flattening
you ought to have been flattening
they ought to have been flattening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I ought not to flatten
you ought not to flatten
she ought not to flatten
we ought not to flatten
you ought not to flatten
they ought not to flatten 	I ought not to flattening
you ought not to flattening
she ought not to flattening
we ought not to flattening
you ought not to flattening
they ought not to flattening	I ought not to have flattened
you ought not to have flattened
she ought not to have flattened
we ought not to have flattened
you ought not to have flattened
they ought not to have flattened	I ought not to have been flattening
you ought not to have been flattening
she ought not to have been flattening
we ought not to have been flattening
you ought not to have been flattening
they ought not to have been flattening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
ought to I flatten?
ought to you flatten?
ought to she flatten?
ought to we flatten?
ought to you flatten?
ought to they flatten? 	ought to I be flattening?
ought to you be flattening?
ought to she be flattening?
ought to we be flattening?
ought to you be flattening?
ought to they be flattening? 	ought to I have flattened?
ought to you have flattened?
ought to she have flattened?
ought to we have flattened?
ought to you have flattened?
ought to they have flattened? 	ought to I have been flattening?
ought to you have been flattening?
ought to she have been flattening?
ought to we have been flattening?
ought to you have been flattening?
ought to they have been flattening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
ought I not to flatten?
ought you not to flatten?
ought she not to flatten?
ought we not to flatten?
ought you not to flatten?
ought they not to flatten? 	ought I not to be flattening?
ought you not to be flattening?
ought she not to be flattening?
ought we not to be flattening?
ought you not to be flattening?
ought they not to be flattening? 	ought I not to have flattened?
ought you not to have flattened?
ought she not to have flattened?
ought we not to have flattened?
ought you not to have flattened?
ought they not to have flattened? 	ought I not to have been flattening?
ought you not to have been flattening?
ought she not to have been flattening?
ought we not to have been flattening?
ought you not to have been flattening?
ought they not to have been flattening?