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