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