I could conceive you could conceive he could conceive we could conceive you could conceive they could conceive
V-ing form
I could be conceiving you could be conceiving he could be conceiving we could be conceiving you could be conceiving they could be conceiving
Perfect
I could have conceived you could have conceived he could have conceived we could have conceived you could have conceived they could have conceived
V-ing perfect
I could have been conceiving you could have been conceiving he could have been conceiving we could have been conceiving you could have been conceiving they could have been conceiving
Negation
Simple form
I could not conceive you could not conceive he could not conceive we could not conceive you could not conceive they could not conceive
V-ing form
I could not be conceiving you could not be conceiving he could not be conceiving we could not be conceiving you could not be conceiving they could not be conceiving
Perfect
I could not have conceived you could not have conceived he could not have conceived we could not have conceived you could not have conceived they could not have conceived
V-ing perfect
I could not have been conceiving you could not have been conceiving he could not have been conceiving we could not have been conceiving you could not have been conceiving they could not have been conceiving
Interrogative form
Simple form
could I conceive? could you conceive? could he conceive? could we conceive? could you conceive? could they conceive?
V-ing form
could I be conceiving? could you be conceiving? could he be conceiving? could we be conceiving? could you be conceiving? could they be conceiving?
Perfect
could I have conceived? could you have conceived? could he have conceived? could we have conceived? could you have conceived? could they have conceived?
V-ing perfect
could I have been conceiving? could you have been conceiving? could he have been conceiving? could we have been conceiving? could you have been conceiving? could they have been conceiving?
Interro-negative form
Simple form
could I not conceive? could you not conceive? could he not conceive? could we not conceive? could you not conceive? could they not conceive?
V-ing form
could I not be conceiving? could you not be conceiving? could he not be conceiving? could we not be conceiving? could you not be conceiving? could they not be conceiving?
Perfect
could I not have conceived? could you not have conceived? could he not have conceived? could we not have conceived? could you not have conceived? could they not have conceived?
V-ing perfect
could I not have been conceiving? could you not have been conceiving? could he not have been conceiving? could we not have been conceiving? could you not have been conceiving? could they not have been conceiving?