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