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