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