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