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