could decease decease
Regular verb: decease decease - decease deceased- decease deceased

, this verb may not exist. Conjugation is given as example.

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could decease decease
you could decease decease
he could decease decease
we could decease decease
you could decease decease
they could decease decease 	I could be decease deceasing
you could be decease deceasing
he could be decease deceasing
we could be decease deceasing
you could be decease deceasing
they could be decease deceasing	I could have decease deceased
you could have decease deceased
he could have decease deceased
we could have decease deceased
you could have decease deceased
they could have decease deceased	I could have been decease deceasing
you could have been decease deceasing
he could have been decease deceasing
we could have been decease deceasing
you could have been decease deceasing
they could have been decease deceasing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't decease decease
you couldn't decease decease
he couldn't decease decease
we couldn't decease decease
you couldn't decease decease
they couldn't decease decease 	I couldn't be decease deceasing
you couldn't be decease deceasing
he couldn't be decease deceasing
we couldn't be decease deceasing
you couldn't be decease deceasing
they couldn't be decease deceasing	I couldn't have decease deceased
you couldn't have decease deceased
he couldn't have decease deceased
we couldn't have decease deceased
you couldn't have decease deceased
they couldn't have decease deceased	I couldn't have been decease deceasing
you couldn't have been decease deceasing
he couldn't have been decease deceasing
we couldn't have been decease deceasing
you couldn't have been decease deceasing
they couldn't have been decease deceasing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I decease decease?
could you decease decease?
could he decease decease?
could we decease decease?
could you decease decease?
could they decease decease? 	could I be decease deceasing?
could you be decease deceasing?
could he be decease deceasing?
could we be decease deceasing?
could you be decease deceasing?
could they be decease deceasing? 	could I have decease deceased?
could you have decease deceased?
could he have decease deceased?
could we have decease deceased?
could you have decease deceased?
could they have decease deceased? 	could I have been decease deceasing?
could you have been decease deceasing?
could he have been decease deceasing?
could we have been decease deceasing?
could you have been decease deceasing?
could they have been decease deceasing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I decease decease?
couldn't you decease decease?
couldn't he decease decease?
couldn't we decease decease?
couldn't you decease decease?
couldn't they decease decease? 	couldn't I be decease deceasing?
couldn't you be decease deceasing?
couldn't he be decease deceasing?
couldn't we be decease deceasing?
couldn't you be decease deceasing?
couldn't they be decease deceasing? 	couldn't I have decease deceased?
couldn't you have decease deceased?
couldn't he have decease deceased?
couldn't we have decease deceased?
couldn't you have decease deceased?
couldn't they have decease deceased? 	couldn't I have been decease deceasing?
couldn't you have been decease deceasing?
couldn't he have been decease deceasing?
couldn't we have been decease deceasing?
couldn't you have been decease deceasing?
couldn't they have been decease deceasing?