could leaven
Verbo regular: leaven - leavened- leavened

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could leaven
you could leaven
he could leaven
we could leaven
you could leaven
they could leaven 	I could be leavening
you could be leavening
he could be leavening
we could be leavening
you could be leavening
they could be leavening	I could have leavened
you could have leavened
he could have leavened
we could have leavened
you could have leavened
they could have leavened	I could have been leavening
you could have been leavening
he could have been leavening
we could have been leavening
you could have been leavening
they could have been leavening	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I couldn't leaven
you couldn't leaven
he couldn't leaven
we couldn't leaven
you couldn't leaven
they couldn't leaven 	I couldn't be leavening
you couldn't be leavening
he couldn't be leavening
we couldn't be leavening
you couldn't be leavening
they couldn't be leavening	I couldn't have leavened
you couldn't have leavened
he couldn't have leavened
we couldn't have leavened
you couldn't have leavened
they couldn't have leavened	I couldn't have been leavening
you couldn't have been leavening
he couldn't have been leavening
we couldn't have been leavening
you couldn't have been leavening
they couldn't have been leavening	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I leaven?
could you leaven?
could he leaven?
could we leaven?
could you leaven?
could they leaven? 	could I be leavening?
could you be leavening?
could he be leavening?
could we be leavening?
could you be leavening?
could they be leavening? 	could I have leavened?
could you have leavened?
could he have leavened?
could we have leavened?
could you have leavened?
could they have leavened? 	could I have been leavening?
could you have been leavening?
could he have been leavening?
could we have been leavening?
could you have been leavening?
could they have been leavening? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
couldn't I leaven?
couldn't you leaven?
couldn't he leaven?
couldn't we leaven?
couldn't you leaven?
couldn't they leaven? 	couldn't I be leavening?
couldn't you be leavening?
couldn't he be leavening?
couldn't we be leavening?
couldn't you be leavening?
couldn't they be leavening? 	couldn't I have leavened?
couldn't you have leavened?
couldn't he have leavened?
couldn't we have leavened?
couldn't you have leavened?
couldn't they have leavened? 	couldn't I have been leavening?
couldn't you have been leavening?
couldn't he have been leavening?
couldn't we have been leavening?
couldn't you have been leavening?
couldn't they have been leavening?