can concern
Verbo regular: concern - concerned- concerned

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I can concern
you can concern
he can concern
we can concern
you can concern
they can concern 	I can be concerning
you can be concerning
he can be concerning
we can be concerning
you can be concerning
they can be concerning	I can have concerned
you can have concerned
he can have concerned
we can have concerned
you can have concerned
they can have concerned	I can have been concerning
you can have been concerning
he can have been concerning
we can have been concerning
you can have been concerning
they can have been concerning	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I can't concern
you can't concern
he can't concern
we can't concern
you can't concern
they can't concern 	I can't be concerning
you can't be concerning
he can't be concerning
we can't be concerning
you can't be concerning
they can't be concerning	I can't have concerned
you can't have concerned
he can't have concerned
we can't have concerned
you can't have concerned
they can't have concerned	I can't have been concerning
you can't have been concerning
he can't have been concerning
we can't have been concerning
you can't have been concerning
they can't have been concerning	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
can I concern?
can you concern?
can he concern?
can we concern?
can you concern?
can they concern? 	can I be concerning?
can you be concerning?
can he be concerning?
can we be concerning?
can you be concerning?
can they be concerning? 	can I have concerned?
can you have concerned?
can he have concerned?
can we have concerned?
can you have concerned?
can they have concerned? 	can I have been concerning?
can you have been concerning?
can he have been concerning?
can we have been concerning?
can you have been concerning?
can they have been concerning? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
can't I concern?
can't you concern?
can't he concern?
can't we concern?
can't you concern?
can't they concern? 	can't I be concerning?
can't you be concerning?
can't he be concerning?
can't we be concerning?
can't you be concerning?
can't they be concerning? 	can't I have concerned?
can't you have concerned?
can't he have concerned?
can't we have concerned?
can't you have concerned?
can't they have concerned? 	can't I have been concerning?
can't you have been concerning?
can't he have been concerning?
can't we have been concerning?
can't you have been concerning?
can't they have been concerning?