can sustain
Verbo regular: sustain - sustained- sustained

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I can sustain
you can sustain
she can sustain
we can sustain
you can sustain
they can sustain 	I can be sustaining
you can be sustaining
she can be sustaining
we can be sustaining
you can be sustaining
they can be sustaining	I can have sustained
you can have sustained
she can have sustained
we can have sustained
you can have sustained
they can have sustained	I can have been sustaining
you can have been sustaining
she can have been sustaining
we can have been sustaining
you can have been sustaining
they can have been sustaining	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I cannot sustain
you cannot sustain
she cannot sustain
we cannot sustain
you cannot sustain
they cannot sustain 	I cannot be sustaining
you cannot be sustaining
she cannot be sustaining
we cannot be sustaining
you cannot be sustaining
they cannot be sustaining	I cannot have sustained
you cannot have sustained
she cannot have sustained
we cannot have sustained
you cannot have sustained
they cannot have sustained	I cannot have been sustaining
you cannot have been sustaining
she cannot have been sustaining
we cannot have been sustaining
you cannot have been sustaining
they cannot have been sustaining	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
can I sustain?
can you sustain?
can she sustain?
can we sustain?
can you sustain?
can they sustain? 	can I be sustaining?
can you be sustaining?
can she be sustaining?
can we be sustaining?
can you be sustaining?
can they be sustaining? 	can I have sustained?
can you have sustained?
can she have sustained?
can we have sustained?
can you have sustained?
can they have sustained? 	can I have been sustaining?
can you have been sustaining?
can she have been sustaining?
can we have been sustaining?
can you have been sustaining?
can they have been sustaining? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
can I not sustain?
can you not sustain?
can she not sustain?
can we not sustain?
can you not sustain?
can they not sustain? 	can I not be sustaining?
can you not be sustaining?
can she not be sustaining?
can we not be sustaining?
can you not be sustaining?
can they not be sustaining? 	can I not have sustained?
can you not have sustained?
can she not have sustained?
can we not have sustained?
can you not have sustained?
can they not have sustained? 	can I not have been sustaining?
can you not have been sustaining?
can she not have been sustaining?
can we not have been sustaining?
can you not have been sustaining?
can they not have been sustaining?