I could harness you could harness she could harness we could harness you could harness they could harness
V-ing form
I could be harnessing you could be harnessing she could be harnessing we could be harnessing you could be harnessing they could be harnessing
Perfect
I could have harnessed you could have harnessed she could have harnessed we could have harnessed you could have harnessed they could have harnessed
V-ing perfect
I could have been harnessing you could have been harnessing she could have been harnessing we could have been harnessing you could have been harnessing they could have been harnessing
Negation
Simple form
I couldn't harness you couldn't harness she couldn't harness we couldn't harness you couldn't harness they couldn't harness
V-ing form
I couldn't be harnessing you couldn't be harnessing she couldn't be harnessing we couldn't be harnessing you couldn't be harnessing they couldn't be harnessing
Perfect
I couldn't have harnessed you couldn't have harnessed she couldn't have harnessed we couldn't have harnessed you couldn't have harnessed they couldn't have harnessed
V-ing perfect
I couldn't have been harnessing you couldn't have been harnessing she couldn't have been harnessing we couldn't have been harnessing you couldn't have been harnessing they couldn't have been harnessing
Interrogative form
Simple form
could I harness? could you harness? could she harness? could we harness? could you harness? could they harness?
V-ing form
could I be harnessing? could you be harnessing? could she be harnessing? could we be harnessing? could you be harnessing? could they be harnessing?
Perfect
could I have harnessed? could you have harnessed? could she have harnessed? could we have harnessed? could you have harnessed? could they have harnessed?
V-ing perfect
could I have been harnessing? could you have been harnessing? could she have been harnessing? could we have been harnessing? could you have been harnessing? could they have been harnessing?
Interro-negative form
Simple form
couldn't I harness? couldn't you harness? couldn't she harness? couldn't we harness? couldn't you harness? couldn't they harness?
V-ing form
couldn't I be harnessing? couldn't you be harnessing? couldn't she be harnessing? couldn't we be harnessing? couldn't you be harnessing? couldn't they be harnessing?
Perfect
couldn't I have harnessed? couldn't you have harnessed? couldn't she have harnessed? couldn't we have harnessed? couldn't you have harnessed? couldn't they have harnessed?
V-ing perfect
couldn't I have been harnessing? couldn't you have been harnessing? couldn't she have been harnessing? couldn't we have been harnessing? couldn't you have been harnessing? couldn't they have been harnessing?