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