can mark
Verbo regular: mark - marked- marked

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I can mark
you can mark
he can mark
we can mark
you can mark
they can mark 	I can be marking
you can be marking
he can be marking
we can be marking
you can be marking
they can be marking	I can have marked
you can have marked
he can have marked
we can have marked
you can have marked
they can have marked	I can have been marking
you can have been marking
he can have been marking
we can have been marking
you can have been marking
they can have been marking	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I cannot mark
you cannot mark
he cannot mark
we cannot mark
you cannot mark
they cannot mark 	I cannot be marking
you cannot be marking
he cannot be marking
we cannot be marking
you cannot be marking
they cannot be marking	I cannot have marked
you cannot have marked
he cannot have marked
we cannot have marked
you cannot have marked
they cannot have marked	I cannot have been marking
you cannot have been marking
he cannot have been marking
we cannot have been marking
you cannot have been marking
they cannot have been marking	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
can I mark?
can you mark?
can he mark?
can we mark?
can you mark?
can they mark? 	can I be marking?
can you be marking?
can he be marking?
can we be marking?
can you be marking?
can they be marking? 	can I have marked?
can you have marked?
can he have marked?
can we have marked?
can you have marked?
can they have marked? 	can I have been marking?
can you have been marking?
can he have been marking?
can we have been marking?
can you have been marking?
can they have been marking? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
can I not mark?
can you not mark?
can he not mark?
can we not mark?
can you not mark?
can they not mark? 	can I not be marking?
can you not be marking?
can he not be marking?
can we not be marking?
can you not be marking?
can they not be marking? 	can I not have marked?
can you not have marked?
can he not have marked?
can we not have marked?
can you not have marked?
can they not have marked? 	can I not have been marking?
can you not have been marking?
can he not have been marking?
can we not have been marking?
can you not have been marking?
can they not have been marking?