can ruin
Regular verb: ruin - ruined- ruined

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can ruin
you can ruin
he can ruin
we can ruin
you can ruin
they can ruin 	I can be ruining
you can be ruining
he can be ruining
we can be ruining
you can be ruining
they can be ruining	I can have ruined
you can have ruined
he can have ruined
we can have ruined
you can have ruined
they can have ruined	I can have been ruining
you can have been ruining
he can have been ruining
we can have been ruining
you can have been ruining
they can have been ruining	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't ruin
you can't ruin
he can't ruin
we can't ruin
you can't ruin
they can't ruin 	I can't be ruining
you can't be ruining
he can't be ruining
we can't be ruining
you can't be ruining
they can't be ruining	I can't have ruined
you can't have ruined
he can't have ruined
we can't have ruined
you can't have ruined
they can't have ruined	I can't have been ruining
you can't have been ruining
he can't have been ruining
we can't have been ruining
you can't have been ruining
they can't have been ruining	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I ruin?
can you ruin?
can he ruin?
can we ruin?
can you ruin?
can they ruin? 	can I be ruining?
can you be ruining?
can he be ruining?
can we be ruining?
can you be ruining?
can they be ruining? 	can I have ruined?
can you have ruined?
can he have ruined?
can we have ruined?
can you have ruined?
can they have ruined? 	can I have been ruining?
can you have been ruining?
can he have been ruining?
can we have been ruining?
can you have been ruining?
can they have been ruining? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I ruin?
can't you ruin?
can't he ruin?
can't we ruin?
can't you ruin?
can't they ruin? 	can't I be ruining?
can't you be ruining?
can't he be ruining?
can't we be ruining?
can't you be ruining?
can't they be ruining? 	can't I have ruined?
can't you have ruined?
can't he have ruined?
can't we have ruined?
can't you have ruined?
can't they have ruined? 	can't I have been ruining?
can't you have been ruining?
can't he have been ruining?
can't we have been ruining?
can't you have been ruining?
can't they have been ruining?