I could conceive you could conceive she could conceive we could conceive you could conceive they could conceive
V-ing form
I could be conceiving you could be conceiving she could be conceiving we could be conceiving you could be conceiving they could be conceiving
Perfect
I could have conceived you could have conceived she 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 she could have been conceiving we could have been conceiving you could have been conceiving they could have been conceiving
Negation
Simple form
I couldn't conceive you couldn't conceive she couldn't conceive we couldn't conceive you couldn't conceive they couldn't conceive
V-ing form
I couldn't be conceiving you couldn't be conceiving she couldn't be conceiving we couldn't be conceiving you couldn't be conceiving they couldn't be conceiving
Perfect
I couldn't have conceived you couldn't have conceived she couldn't have conceived we couldn't have conceived you couldn't have conceived they couldn't have conceived
V-ing perfect
I couldn't have been conceiving you couldn't have been conceiving she couldn't have been conceiving we couldn't have been conceiving you couldn't have been conceiving they couldn't have been conceiving
Interrogative form
Simple form
could I conceive? could you conceive? could she conceive? could we conceive? could you conceive? could they conceive?
V-ing form
could I be conceiving? could you be conceiving? could she be conceiving? could we be conceiving? could you be conceiving? could they be conceiving?
Perfect
could I have conceived? could you have conceived? could she 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 she have been conceiving? could we have been conceiving? could you have been conceiving? could they have been conceiving?
Interro-negative form
Simple form
couldn't I conceive? couldn't you conceive? couldn't she conceive? couldn't we conceive? couldn't you conceive? couldn't they conceive?
V-ing form
couldn't I be conceiving? couldn't you be conceiving? couldn't she be conceiving? couldn't we be conceiving? couldn't you be conceiving? couldn't they be conceiving?
Perfect
couldn't I have conceived? couldn't you have conceived? couldn't she have conceived? couldn't we have conceived? couldn't you have conceived? couldn't they have conceived?
V-ing perfect
couldn't I have been conceiving? couldn't you have been conceiving? couldn't she have been conceiving? couldn't we have been conceiving? couldn't you have been conceiving? couldn't they have been conceiving?