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