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