could deteriorate
Verbo regular: deteriorate - deteriorated- deteriorated

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could deteriorate
you could deteriorate
she could deteriorate
we could deteriorate
you could deteriorate
they could deteriorate 	I could be deteriorating
you could be deteriorating
she could be deteriorating
we could be deteriorating
you could be deteriorating
they could be deteriorating	I could have deteriorated
you could have deteriorated
she could have deteriorated
we could have deteriorated
you could have deteriorated
they could have deteriorated	I could have been deteriorating
you could have been deteriorating
she could have been deteriorating
we could have been deteriorating
you could have been deteriorating
they could have been deteriorating	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't deteriorate
you couldn't deteriorate
she couldn't deteriorate
we couldn't deteriorate
you couldn't deteriorate
they couldn't deteriorate 	I couldn't be deteriorating
you couldn't be deteriorating
she couldn't be deteriorating
we couldn't be deteriorating
you couldn't be deteriorating
they couldn't be deteriorating	I couldn't have deteriorated
you couldn't have deteriorated
she couldn't have deteriorated
we couldn't have deteriorated
you couldn't have deteriorated
they couldn't have deteriorated	I couldn't have been deteriorating
you couldn't have been deteriorating
she couldn't have been deteriorating
we couldn't have been deteriorating
you couldn't have been deteriorating
they couldn't have been deteriorating	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I deteriorate?
could you deteriorate?
could she deteriorate?
could we deteriorate?
could you deteriorate?
could they deteriorate? 	could I be deteriorating?
could you be deteriorating?
could she be deteriorating?
could we be deteriorating?
could you be deteriorating?
could they be deteriorating? 	could I have deteriorated?
could you have deteriorated?
could she have deteriorated?
could we have deteriorated?
could you have deteriorated?
could they have deteriorated? 	could I have been deteriorating?
could you have been deteriorating?
could she have been deteriorating?
could we have been deteriorating?
could you have been deteriorating?
could they have been deteriorating? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I deteriorate?
couldn't you deteriorate?
couldn't she deteriorate?
couldn't we deteriorate?
couldn't you deteriorate?
couldn't they deteriorate? 	couldn't I be deteriorating?
couldn't you be deteriorating?
couldn't she be deteriorating?
couldn't we be deteriorating?
couldn't you be deteriorating?
couldn't they be deteriorating? 	couldn't I have deteriorated?
couldn't you have deteriorated?
couldn't she have deteriorated?
couldn't we have deteriorated?
couldn't you have deteriorated?
couldn't they have deteriorated? 	couldn't I have been deteriorating?
couldn't you have been deteriorating?
couldn't she have been deteriorating?
couldn't we have been deteriorating?
couldn't you have been deteriorating?
couldn't they have been deteriorating?