can perturb
Regular verb: perturb - perturbed- perturbed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can perturb
you can perturb
he can perturb
we can perturb
you can perturb
they can perturb 	I can be perturbing
you can be perturbing
he can be perturbing
we can be perturbing
you can be perturbing
they can be perturbing	I can have perturbed
you can have perturbed
he can have perturbed
we can have perturbed
you can have perturbed
they can have perturbed	I can have been perturbing
you can have been perturbing
he can have been perturbing
we can have been perturbing
you can have been perturbing
they can have been perturbing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't perturb
you can't perturb
he can't perturb
we can't perturb
you can't perturb
they can't perturb 	I can't be perturbing
you can't be perturbing
he can't be perturbing
we can't be perturbing
you can't be perturbing
they can't be perturbing	I can't have perturbed
you can't have perturbed
he can't have perturbed
we can't have perturbed
you can't have perturbed
they can't have perturbed	I can't have been perturbing
you can't have been perturbing
he can't have been perturbing
we can't have been perturbing
you can't have been perturbing
they can't have been perturbing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I perturb?
can you perturb?
can he perturb?
can we perturb?
can you perturb?
can they perturb? 	can I be perturbing?
can you be perturbing?
can he be perturbing?
can we be perturbing?
can you be perturbing?
can they be perturbing? 	can I have perturbed?
can you have perturbed?
can he have perturbed?
can we have perturbed?
can you have perturbed?
can they have perturbed? 	can I have been perturbing?
can you have been perturbing?
can he have been perturbing?
can we have been perturbing?
can you have been perturbing?
can they have been perturbing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I perturb?
can't you perturb?
can't he perturb?
can't we perturb?
can't you perturb?
can't they perturb? 	can't I be perturbing?
can't you be perturbing?
can't he be perturbing?
can't we be perturbing?
can't you be perturbing?
can't they be perturbing? 	can't I have perturbed?
can't you have perturbed?
can't he have perturbed?
can't we have perturbed?
can't you have perturbed?
can't they have perturbed? 	can't I have been perturbing?
can't you have been perturbing?
can't he have been perturbing?
can't we have been perturbing?
can't you have been perturbing?
can't they have been perturbing?