I could interrogate you could interrogate he could interrogate we could interrogate you could interrogate they could interrogate
V-ing form
I could be interrogating you could be interrogating he could be interrogating we could be interrogating you could be interrogating they could be interrogating
Perfect
I could have interrogated you could have interrogated he could have interrogated we could have interrogated you could have interrogated they could have interrogated
V-ing perfect
I could have been interrogating you could have been interrogating he could have been interrogating we could have been interrogating you could have been interrogating they could have been interrogating
Negation
Simple form
I couldn't interrogate you couldn't interrogate he couldn't interrogate we couldn't interrogate you couldn't interrogate they couldn't interrogate
V-ing form
I couldn't be interrogating you couldn't be interrogating he couldn't be interrogating we couldn't be interrogating you couldn't be interrogating they couldn't be interrogating
Perfect
I couldn't have interrogated you couldn't have interrogated he couldn't have interrogated we couldn't have interrogated you couldn't have interrogated they couldn't have interrogated
V-ing perfect
I couldn't have been interrogating you couldn't have been interrogating he couldn't have been interrogating we couldn't have been interrogating you couldn't have been interrogating they couldn't have been interrogating
Interrogative form
Simple form
could I interrogate? could you interrogate? could he interrogate? could we interrogate? could you interrogate? could they interrogate?
V-ing form
could I be interrogating? could you be interrogating? could he be interrogating? could we be interrogating? could you be interrogating? could they be interrogating?
Perfect
could I have interrogated? could you have interrogated? could he have interrogated? could we have interrogated? could you have interrogated? could they have interrogated?
V-ing perfect
could I have been interrogating? could you have been interrogating? could he have been interrogating? could we have been interrogating? could you have been interrogating? could they have been interrogating?
Interro-negative form
Simple form
couldn't I interrogate? couldn't you interrogate? couldn't he interrogate? couldn't we interrogate? couldn't you interrogate? couldn't they interrogate?
V-ing form
couldn't I be interrogating? couldn't you be interrogating? couldn't he be interrogating? couldn't we be interrogating? couldn't you be interrogating? couldn't they be interrogating?
Perfect
couldn't I have interrogated? couldn't you have interrogated? couldn't he have interrogated? couldn't we have interrogated? couldn't you have interrogated? couldn't they have interrogated?
V-ing perfect
couldn't I have been interrogating? couldn't you have been interrogating? couldn't he have been interrogating? couldn't we have been interrogating? couldn't you have been interrogating? couldn't they have been interrogating?