ought to strengthen
Regular verb: strengthen - strengthened- strengthened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I ought to strengthen
you ought to strengthen
she ought to strengthen
we ought to strengthen
you ought to strengthen
they ought to strengthen 	I ought to be strengthening
you ought to be strengthening
she ought to be strengthening
we ought to be strengthening
you ought to be strengthening
they ought to be strengthening	I ought to have strengthened
you ought to have strengthened
she ought to have strengthened
we ought to have strengthened
you ought to have strengthened
they ought to have strengthened	I ought to have been strengthening
you ought to have been strengthening
she ought to have been strengthening
we ought to have been strengthening
you ought to have been strengthening
they ought to have been strengthening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I ought not to strengthen
you ought not to strengthen
she ought not to strengthen
we ought not to strengthen
you ought not to strengthen
they ought not to strengthen 	I ought not to strengthening
you ought not to strengthening
she ought not to strengthening
we ought not to strengthening
you ought not to strengthening
they ought not to strengthening	I ought not to have strengthened
you ought not to have strengthened
she ought not to have strengthened
we ought not to have strengthened
you ought not to have strengthened
they ought not to have strengthened	I ought not to have been strengthening
you ought not to have been strengthening
she ought not to have been strengthening
we ought not to have been strengthening
you ought not to have been strengthening
they ought not to have been strengthening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
ought to I strengthen?
ought to you strengthen?
ought to she strengthen?
ought to we strengthen?
ought to you strengthen?
ought to they strengthen? 	ought to I be strengthening?
ought to you be strengthening?
ought to she be strengthening?
ought to we be strengthening?
ought to you be strengthening?
ought to they be strengthening? 	ought to I have strengthened?
ought to you have strengthened?
ought to she have strengthened?
ought to we have strengthened?
ought to you have strengthened?
ought to they have strengthened? 	ought to I have been strengthening?
ought to you have been strengthening?
ought to she have been strengthening?
ought to we have been strengthening?
ought to you have been strengthening?
ought to they have been strengthening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
ought I not to strengthen?
ought you not to strengthen?
ought she not to strengthen?
ought we not to strengthen?
ought you not to strengthen?
ought they not to strengthen? 	ought I not to be strengthening?
ought you not to be strengthening?
ought she not to be strengthening?
ought we not to be strengthening?
ought you not to be strengthening?
ought they not to be strengthening? 	ought I not to have strengthened?
ought you not to have strengthened?
ought she not to have strengthened?
ought we not to have strengthened?
ought you not to have strengthened?
ought they not to have strengthened? 	ought I not to have been strengthening?
ought you not to have been strengthening?
ought she not to have been strengthening?
ought we not to have been strengthening?
ought you not to have been strengthening?
ought they not to have been strengthening?