shall decease
Regular verb: decease - deceased- deceased

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

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

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

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