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