could disturb
Regular verb: disturb - disturbed- disturbed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could disturb
you could disturb
she could disturb
we could disturb
you could disturb
they could disturb 	I could be disturbing
you could be disturbing
she could be disturbing
we could be disturbing
you could be disturbing
they could be disturbing	I could have disturbed
you could have disturbed
she could have disturbed
we could have disturbed
you could have disturbed
they could have disturbed	I could have been disturbing
you could have been disturbing
she could have been disturbing
we could have been disturbing
you could have been disturbing
they could have been disturbing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't disturb
you couldn't disturb
she couldn't disturb
we couldn't disturb
you couldn't disturb
they couldn't disturb 	I couldn't be disturbing
you couldn't be disturbing
she couldn't be disturbing
we couldn't be disturbing
you couldn't be disturbing
they couldn't be disturbing	I couldn't have disturbed
you couldn't have disturbed
she couldn't have disturbed
we couldn't have disturbed
you couldn't have disturbed
they couldn't have disturbed	I couldn't have been disturbing
you couldn't have been disturbing
she couldn't have been disturbing
we couldn't have been disturbing
you couldn't have been disturbing
they couldn't have been disturbing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I disturb?
could you disturb?
could she disturb?
could we disturb?
could you disturb?
could they disturb? 	could I be disturbing?
could you be disturbing?
could she be disturbing?
could we be disturbing?
could you be disturbing?
could they be disturbing? 	could I have disturbed?
could you have disturbed?
could she have disturbed?
could we have disturbed?
could you have disturbed?
could they have disturbed? 	could I have been disturbing?
could you have been disturbing?
could she have been disturbing?
could we have been disturbing?
could you have been disturbing?
could they have been disturbing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I disturb?
couldn't you disturb?
couldn't she disturb?
couldn't we disturb?
couldn't you disturb?
couldn't they disturb? 	couldn't I be disturbing?
couldn't you be disturbing?
couldn't she be disturbing?
couldn't we be disturbing?
couldn't you be disturbing?
couldn't they be disturbing? 	couldn't I have disturbed?
couldn't you have disturbed?
couldn't she have disturbed?
couldn't we have disturbed?
couldn't you have disturbed?
couldn't they have disturbed? 	couldn't I have been disturbing?
couldn't you have been disturbing?
couldn't she have been disturbing?
couldn't we have been disturbing?
couldn't you have been disturbing?
couldn't they have been disturbing?