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