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