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