could stagnate
Verbo regular: stagnate - stagnated- stagnated

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could stagnate
you could stagnate
he could stagnate
we could stagnate
you could stagnate
they could stagnate 	I could be stagnating
you could be stagnating
he could be stagnating
we could be stagnating
you could be stagnating
they could be stagnating	I could have stagnated
you could have stagnated
he could have stagnated
we could have stagnated
you could have stagnated
they could have stagnated	I could have been stagnating
you could have been stagnating
he could have been stagnating
we could have been stagnating
you could have been stagnating
they could have been stagnating	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't stagnate
you couldn't stagnate
he couldn't stagnate
we couldn't stagnate
you couldn't stagnate
they couldn't stagnate 	I couldn't be stagnating
you couldn't be stagnating
he couldn't be stagnating
we couldn't be stagnating
you couldn't be stagnating
they couldn't be stagnating	I couldn't have stagnated
you couldn't have stagnated
he couldn't have stagnated
we couldn't have stagnated
you couldn't have stagnated
they couldn't have stagnated	I couldn't have been stagnating
you couldn't have been stagnating
he couldn't have been stagnating
we couldn't have been stagnating
you couldn't have been stagnating
they couldn't have been stagnating	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I stagnate?
could you stagnate?
could he stagnate?
could we stagnate?
could you stagnate?
could they stagnate? 	could I be stagnating?
could you be stagnating?
could he be stagnating?
could we be stagnating?
could you be stagnating?
could they be stagnating? 	could I have stagnated?
could you have stagnated?
could he have stagnated?
could we have stagnated?
could you have stagnated?
could they have stagnated? 	could I have been stagnating?
could you have been stagnating?
could he have been stagnating?
could we have been stagnating?
could you have been stagnating?
could they have been stagnating? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I stagnate?
couldn't you stagnate?
couldn't he stagnate?
couldn't we stagnate?
couldn't you stagnate?
couldn't they stagnate? 	couldn't I be stagnating?
couldn't you be stagnating?
couldn't he be stagnating?
couldn't we be stagnating?
couldn't you be stagnating?
couldn't they be stagnating? 	couldn't I have stagnated?
couldn't you have stagnated?
couldn't he have stagnated?
couldn't we have stagnated?
couldn't you have stagnated?
couldn't they have stagnated? 	couldn't I have been stagnating?
couldn't you have been stagnating?
couldn't he have been stagnating?
couldn't we have been stagnating?
couldn't you have been stagnating?
couldn't they have been stagnating?