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