I can spur you can spur he can spur we can spur you can spur they can spur
V-ing form
I can be spurring you can be spurring he can be spurring we can be spurring you can be spurring they can be spurring
Perfect
I can have spurred you can have spurred he can have spurred we can have spurred you can have spurred they can have spurred
V-ing perfect
I can have been spurring you can have been spurring he can have been spurring we can have been spurring you can have been spurring they can have been spurring
Negation
Simple form
I cannot spur you cannot spur he cannot spur we cannot spur you cannot spur they cannot spur
V-ing form
I cannot be spurring you cannot be spurring he cannot be spurring we cannot be spurring you cannot be spurring they cannot be spurring
Perfect
I cannot have spurred you cannot have spurred he cannot have spurred we cannot have spurred you cannot have spurred they cannot have spurred
V-ing perfect
I cannot have been spurring you cannot have been spurring he cannot have been spurring we cannot have been spurring you cannot have been spurring they cannot have been spurring
Interrogative form
Simple form
can I spur? can you spur? can he spur? can we spur? can you spur? can they spur?
V-ing form
can I be spurring? can you be spurring? can he be spurring? can we be spurring? can you be spurring? can they be spurring?
Perfect
can I have spurred? can you have spurred? can he have spurred? can we have spurred? can you have spurred? can they have spurred?
V-ing perfect
can I have been spurring? can you have been spurring? can he have been spurring? can we have been spurring? can you have been spurring? can they have been spurring?
Interro-negative form
Simple form
can I not spur? can you not spur? can he not spur? can we not spur? can you not spur? can they not spur?
V-ing form
can I not be spurring? can you not be spurring? can he not be spurring? can we not be spurring? can you not be spurring? can they not be spurring?
Perfect
can I not have spurred? can you not have spurred? can he not have spurred? can we not have spurred? can you not have spurred? can they not have spurred?
V-ing perfect
can I not have been spurring? can you not have been spurring? can he not have been spurring? can we not have been spurring? can you not have been spurring? can they not have been spurring?