can castle
Regular verb: castle - castled- castled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can castle
you can castle
he can castle
we can castle
you can castle
they can castle 	I can be castling
you can be castling
he can be castling
we can be castling
you can be castling
they can be castling	I can have castled
you can have castled
he can have castled
we can have castled
you can have castled
they can have castled	I can have been castling
you can have been castling
he can have been castling
we can have been castling
you can have been castling
they can have been castling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot castle
you cannot castle
he cannot castle
we cannot castle
you cannot castle
they cannot castle 	I cannot be castling
you cannot be castling
he cannot be castling
we cannot be castling
you cannot be castling
they cannot be castling	I cannot have castled
you cannot have castled
he cannot have castled
we cannot have castled
you cannot have castled
they cannot have castled	I cannot have been castling
you cannot have been castling
he cannot have been castling
we cannot have been castling
you cannot have been castling
they cannot have been castling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I castle?
can you castle?
can he castle?
can we castle?
can you castle?
can they castle? 	can I be castling?
can you be castling?
can he be castling?
can we be castling?
can you be castling?
can they be castling? 	can I have castled?
can you have castled?
can he have castled?
can we have castled?
can you have castled?
can they have castled? 	can I have been castling?
can you have been castling?
can he have been castling?
can we have been castling?
can you have been castling?
can they have been castling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not castle?
can you not castle?
can he not castle?
can we not castle?
can you not castle?
can they not castle? 	can I not be castling?
can you not be castling?
can he not be castling?
can we not be castling?
can you not be castling?
can they not be castling? 	can I not have castled?
can you not have castled?
can he not have castled?
can we not have castled?
can you not have castled?
can they not have castled? 	can I not have been castling?
can you not have been castling?
can he not have been castling?
can we not have been castling?
can you not have been castling?
can they not have been castling?