could fertilize
Verbo regular: fertilize - fertilized- fertilized

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could fertilize
you could fertilize
he could fertilize
we could fertilize
you could fertilize
they could fertilize 	I could be fertilizing
you could be fertilizing
he could be fertilizing
we could be fertilizing
you could be fertilizing
they could be fertilizing	I could have fertilized
you could have fertilized
he could have fertilized
we could have fertilized
you could have fertilized
they could have fertilized	I could have been fertilizing
you could have been fertilizing
he could have been fertilizing
we could have been fertilizing
you could have been fertilizing
they could have been fertilizing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not fertilize
you could not fertilize
he could not fertilize
we could not fertilize
you could not fertilize
they could not fertilize 	I could not be fertilizing
you could not be fertilizing
he could not be fertilizing
we could not be fertilizing
you could not be fertilizing
they could not be fertilizing	I could not have fertilized
you could not have fertilized
he could not have fertilized
we could not have fertilized
you could not have fertilized
they could not have fertilized	I could not have been fertilizing
you could not have been fertilizing
he could not have been fertilizing
we could not have been fertilizing
you could not have been fertilizing
they could not have been fertilizing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I fertilize?
could you fertilize?
could he fertilize?
could we fertilize?
could you fertilize?
could they fertilize? 	could I be fertilizing?
could you be fertilizing?
could he be fertilizing?
could we be fertilizing?
could you be fertilizing?
could they be fertilizing? 	could I have fertilized?
could you have fertilized?
could he have fertilized?
could we have fertilized?
could you have fertilized?
could they have fertilized? 	could I have been fertilizing?
could you have been fertilizing?
could he have been fertilizing?
could we have been fertilizing?
could you have been fertilizing?
could they have been fertilizing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not fertilize?
could you not fertilize?
could he not fertilize?
could we not fertilize?
could you not fertilize?
could they not fertilize? 	could I not be fertilizing?
could you not be fertilizing?
could he not be fertilizing?
could we not be fertilizing?
could you not be fertilizing?
could they not be fertilizing? 	could I not have fertilized?
could you not have fertilized?
could he not have fertilized?
could we not have fertilized?
could you not have fertilized?
could they not have fertilized? 	could I not have been fertilizing?
could you not have been fertilizing?
could he not have been fertilizing?
could we not have been fertilizing?
could you not have been fertilizing?
could they not have been fertilizing?