could unseal
Regular verb: unseal - unsealed- unsealed

Affirmation 	
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I could unseal
you could unseal
she could unseal
we could unseal
you could unseal
they could unseal 	I could be unsealing
you could be unsealing
she could be unsealing
we could be unsealing
you could be unsealing
they could be unsealing	I could have unsealed
you could have unsealed
she could have unsealed
we could have unsealed
you could have unsealed
they could have unsealed	I could have been unsealing
you could have been unsealing
she could have been unsealing
we could have been unsealing
you could have been unsealing
they could have been unsealing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't unseal
you couldn't unseal
she couldn't unseal
we couldn't unseal
you couldn't unseal
they couldn't unseal 	I couldn't be unsealing
you couldn't be unsealing
she couldn't be unsealing
we couldn't be unsealing
you couldn't be unsealing
they couldn't be unsealing	I couldn't have unsealed
you couldn't have unsealed
she couldn't have unsealed
we couldn't have unsealed
you couldn't have unsealed
they couldn't have unsealed	I couldn't have been unsealing
you couldn't have been unsealing
she couldn't have been unsealing
we couldn't have been unsealing
you couldn't have been unsealing
they couldn't have been unsealing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I unseal?
could you unseal?
could she unseal?
could we unseal?
could you unseal?
could they unseal? 	could I be unsealing?
could you be unsealing?
could she be unsealing?
could we be unsealing?
could you be unsealing?
could they be unsealing? 	could I have unsealed?
could you have unsealed?
could she have unsealed?
could we have unsealed?
could you have unsealed?
could they have unsealed? 	could I have been unsealing?
could you have been unsealing?
could she have been unsealing?
could we have been unsealing?
could you have been unsealing?
could they have been unsealing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I unseal?
couldn't you unseal?
couldn't she unseal?
couldn't we unseal?
couldn't you unseal?
couldn't they unseal? 	couldn't I be unsealing?
couldn't you be unsealing?
couldn't she be unsealing?
couldn't we be unsealing?
couldn't you be unsealing?
couldn't they be unsealing? 	couldn't I have unsealed?
couldn't you have unsealed?
couldn't she have unsealed?
couldn't we have unsealed?
couldn't you have unsealed?
couldn't they have unsealed? 	couldn't I have been unsealing?
couldn't you have been unsealing?
couldn't she have been unsealing?
couldn't we have been unsealing?
couldn't you have been unsealing?
couldn't they have been unsealing?