I can crab you can crab she can crab we can crab you can crab they can crab
V-ing form
I can be crabbing you can be crabbing she can be crabbing we can be crabbing you can be crabbing they can be crabbing
Perfect
I can have crabbed you can have crabbed she can have crabbed we can have crabbed you can have crabbed they can have crabbed
V-ing perfect
I can have been crabbing you can have been crabbing she can have been crabbing we can have been crabbing you can have been crabbing they can have been crabbing
Negation
Simple form
I cannot crab you cannot crab she cannot crab we cannot crab you cannot crab they cannot crab
V-ing form
I cannot be crabbing you cannot be crabbing she cannot be crabbing we cannot be crabbing you cannot be crabbing they cannot be crabbing
Perfect
I cannot have crabbed you cannot have crabbed she cannot have crabbed we cannot have crabbed you cannot have crabbed they cannot have crabbed
V-ing perfect
I cannot have been crabbing you cannot have been crabbing she cannot have been crabbing we cannot have been crabbing you cannot have been crabbing they cannot have been crabbing
Interrogative form
Simple form
can I crab? can you crab? can she crab? can we crab? can you crab? can they crab?
V-ing form
can I be crabbing? can you be crabbing? can she be crabbing? can we be crabbing? can you be crabbing? can they be crabbing?
Perfect
can I have crabbed? can you have crabbed? can she have crabbed? can we have crabbed? can you have crabbed? can they have crabbed?
V-ing perfect
can I have been crabbing? can you have been crabbing? can she have been crabbing? can we have been crabbing? can you have been crabbing? can they have been crabbing?
Interro-negative form
Simple form
can I not crab? can you not crab? can she not crab? can we not crab? can you not crab? can they not crab?
V-ing form
can I not be crabbing? can you not be crabbing? can she not be crabbing? can we not be crabbing? can you not be crabbing? can they not be crabbing?
Perfect
can I not have crabbed? can you not have crabbed? can she not have crabbed? can we not have crabbed? can you not have crabbed? can they not have crabbed?
V-ing perfect
can I not have been crabbing? can you not have been crabbing? can she not have been crabbing? can we not have been crabbing? can you not have been crabbing? can they not have been crabbing?