could stalk
Verbo regular: stalk - stalked- stalked

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could stalk
you could stalk
he could stalk
we could stalk
you could stalk
they could stalk 	I could be stalking
you could be stalking
he could be stalking
we could be stalking
you could be stalking
they could be stalking	I could have stalked
you could have stalked
he could have stalked
we could have stalked
you could have stalked
they could have stalked	I could have been stalking
you could have been stalking
he could have been stalking
we could have been stalking
you could have been stalking
they could have been stalking	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't stalk
you couldn't stalk
he couldn't stalk
we couldn't stalk
you couldn't stalk
they couldn't stalk 	I couldn't be stalking
you couldn't be stalking
he couldn't be stalking
we couldn't be stalking
you couldn't be stalking
they couldn't be stalking	I couldn't have stalked
you couldn't have stalked
he couldn't have stalked
we couldn't have stalked
you couldn't have stalked
they couldn't have stalked	I couldn't have been stalking
you couldn't have been stalking
he couldn't have been stalking
we couldn't have been stalking
you couldn't have been stalking
they couldn't have been stalking	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I stalk?
could you stalk?
could he stalk?
could we stalk?
could you stalk?
could they stalk? 	could I be stalking?
could you be stalking?
could he be stalking?
could we be stalking?
could you be stalking?
could they be stalking? 	could I have stalked?
could you have stalked?
could he have stalked?
could we have stalked?
could you have stalked?
could they have stalked? 	could I have been stalking?
could you have been stalking?
could he have been stalking?
could we have been stalking?
could you have been stalking?
could they have been stalking? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I stalk?
couldn't you stalk?
couldn't he stalk?
couldn't we stalk?
couldn't you stalk?
couldn't they stalk? 	couldn't I be stalking?
couldn't you be stalking?
couldn't he be stalking?
couldn't we be stalking?
couldn't you be stalking?
couldn't they be stalking? 	couldn't I have stalked?
couldn't you have stalked?
couldn't he have stalked?
couldn't we have stalked?
couldn't you have stalked?
couldn't they have stalked? 	couldn't I have been stalking?
couldn't you have been stalking?
couldn't he have been stalking?
couldn't we have been stalking?
couldn't you have been stalking?
couldn't they have been stalking?