could percuss
Regular verb: percuss - percussed- percussed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could percuss
you could percuss
she could percuss
we could percuss
you could percuss
they could percuss 	I could be percussing
you could be percussing
she could be percussing
we could be percussing
you could be percussing
they could be percussing	I could have percussed
you could have percussed
she could have percussed
we could have percussed
you could have percussed
they could have percussed	I could have been percussing
you could have been percussing
she could have been percussing
we could have been percussing
you could have been percussing
they could have been percussing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't percuss
you couldn't percuss
she couldn't percuss
we couldn't percuss
you couldn't percuss
they couldn't percuss 	I couldn't be percussing
you couldn't be percussing
she couldn't be percussing
we couldn't be percussing
you couldn't be percussing
they couldn't be percussing	I couldn't have percussed
you couldn't have percussed
she couldn't have percussed
we couldn't have percussed
you couldn't have percussed
they couldn't have percussed	I couldn't have been percussing
you couldn't have been percussing
she couldn't have been percussing
we couldn't have been percussing
you couldn't have been percussing
they couldn't have been percussing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I percuss?
could you percuss?
could she percuss?
could we percuss?
could you percuss?
could they percuss? 	could I be percussing?
could you be percussing?
could she be percussing?
could we be percussing?
could you be percussing?
could they be percussing? 	could I have percussed?
could you have percussed?
could she have percussed?
could we have percussed?
could you have percussed?
could they have percussed? 	could I have been percussing?
could you have been percussing?
could she have been percussing?
could we have been percussing?
could you have been percussing?
could they have been percussing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I percuss?
couldn't you percuss?
couldn't she percuss?
couldn't we percuss?
couldn't you percuss?
couldn't they percuss? 	couldn't I be percussing?
couldn't you be percussing?
couldn't she be percussing?
couldn't we be percussing?
couldn't you be percussing?
couldn't they be percussing? 	couldn't I have percussed?
couldn't you have percussed?
couldn't she have percussed?
couldn't we have percussed?
couldn't you have percussed?
couldn't they have percussed? 	couldn't I have been percussing?
couldn't you have been percussing?
couldn't she have been percussing?
couldn't we have been percussing?
couldn't you have been percussing?
couldn't they have been percussing?