could doubt
Verbo regular: doubt - doubted- doubted

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could doubt
you could doubt
he could doubt
we could doubt
you could doubt
they could doubt 	I could be doubting
you could be doubting
he could be doubting
we could be doubting
you could be doubting
they could be doubting	I could have doubted
you could have doubted
he could have doubted
we could have doubted
you could have doubted
they could have doubted	I could have been doubting
you could have been doubting
he could have been doubting
we could have been doubting
you could have been doubting
they could have been doubting	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't doubt
you couldn't doubt
he couldn't doubt
we couldn't doubt
you couldn't doubt
they couldn't doubt 	I couldn't be doubting
you couldn't be doubting
he couldn't be doubting
we couldn't be doubting
you couldn't be doubting
they couldn't be doubting	I couldn't have doubted
you couldn't have doubted
he couldn't have doubted
we couldn't have doubted
you couldn't have doubted
they couldn't have doubted	I couldn't have been doubting
you couldn't have been doubting
he couldn't have been doubting
we couldn't have been doubting
you couldn't have been doubting
they couldn't have been doubting	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I doubt?
could you doubt?
could he doubt?
could we doubt?
could you doubt?
could they doubt? 	could I be doubting?
could you be doubting?
could he be doubting?
could we be doubting?
could you be doubting?
could they be doubting? 	could I have doubted?
could you have doubted?
could he have doubted?
could we have doubted?
could you have doubted?
could they have doubted? 	could I have been doubting?
could you have been doubting?
could he have been doubting?
could we have been doubting?
could you have been doubting?
could they have been doubting? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I doubt?
couldn't you doubt?
couldn't he doubt?
couldn't we doubt?
couldn't you doubt?
couldn't they doubt? 	couldn't I be doubting?
couldn't you be doubting?
couldn't he be doubting?
couldn't we be doubting?
couldn't you be doubting?
couldn't they be doubting? 	couldn't I have doubted?
couldn't you have doubted?
couldn't he have doubted?
couldn't we have doubted?
couldn't you have doubted?
couldn't they have doubted? 	couldn't I have been doubting?
couldn't you have been doubting?
couldn't he have been doubting?
couldn't we have been doubting?
couldn't you have been doubting?
couldn't they have been doubting?