I could amass you could amass he could amass we could amass you could amass they could amass
V-ing form
I could be amassing you could be amassing he could be amassing we could be amassing you could be amassing they could be amassing
Perfect
I could have amassed you could have amassed he could have amassed we could have amassed you could have amassed they could have amassed
V-ing perfect
I could have been amassing you could have been amassing he could have been amassing we could have been amassing you could have been amassing they could have been amassing
Negation
Simple form
I could not amass you could not amass he could not amass we could not amass you could not amass they could not amass
V-ing form
I could not be amassing you could not be amassing he could not be amassing we could not be amassing you could not be amassing they could not be amassing
Perfect
I could not have amassed you could not have amassed he could not have amassed we could not have amassed you could not have amassed they could not have amassed
V-ing perfect
I could not have been amassing you could not have been amassing he could not have been amassing we could not have been amassing you could not have been amassing they could not have been amassing
Interrogative form
Simple form
could I amass? could you amass? could he amass? could we amass? could you amass? could they amass?
V-ing form
could I be amassing? could you be amassing? could he be amassing? could we be amassing? could you be amassing? could they be amassing?
Perfect
could I have amassed? could you have amassed? could he have amassed? could we have amassed? could you have amassed? could they have amassed?
V-ing perfect
could I have been amassing? could you have been amassing? could he have been amassing? could we have been amassing? could you have been amassing? could they have been amassing?
Interro-negative form
Simple form
could I not amass? could you not amass? could he not amass? could we not amass? could you not amass? could they not amass?
V-ing form
could I not be amassing? could you not be amassing? could he not be amassing? could we not be amassing? could you not be amassing? could they not be amassing?
Perfect
could I not have amassed? could you not have amassed? could he not have amassed? could we not have amassed? could you not have amassed? could they not have amassed?
V-ing perfect
could I not have been amassing? could you not have been amassing? could he not have been amassing? could we not have been amassing? could you not have been amassing? could they not have been amassing?