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