could pith
Regular verb: pith - pithed- pithed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could pith
you could pith
she could pith
we could pith
you could pith
they could pith 	I could be pithing
you could be pithing
she could be pithing
we could be pithing
you could be pithing
they could be pithing	I could have pithed
you could have pithed
she could have pithed
we could have pithed
you could have pithed
they could have pithed	I could have been pithing
you could have been pithing
she could have been pithing
we could have been pithing
you could have been pithing
they could have been pithing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't pith
you couldn't pith
she couldn't pith
we couldn't pith
you couldn't pith
they couldn't pith 	I couldn't be pithing
you couldn't be pithing
she couldn't be pithing
we couldn't be pithing
you couldn't be pithing
they couldn't be pithing	I couldn't have pithed
you couldn't have pithed
she couldn't have pithed
we couldn't have pithed
you couldn't have pithed
they couldn't have pithed	I couldn't have been pithing
you couldn't have been pithing
she couldn't have been pithing
we couldn't have been pithing
you couldn't have been pithing
they couldn't have been pithing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I pith?
could you pith?
could she pith?
could we pith?
could you pith?
could they pith? 	could I be pithing?
could you be pithing?
could she be pithing?
could we be pithing?
could you be pithing?
could they be pithing? 	could I have pithed?
could you have pithed?
could she have pithed?
could we have pithed?
could you have pithed?
could they have pithed? 	could I have been pithing?
could you have been pithing?
could she have been pithing?
could we have been pithing?
could you have been pithing?
could they have been pithing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I pith?
couldn't you pith?
couldn't she pith?
couldn't we pith?
couldn't you pith?
couldn't they pith? 	couldn't I be pithing?
couldn't you be pithing?
couldn't she be pithing?
couldn't we be pithing?
couldn't you be pithing?
couldn't they be pithing? 	couldn't I have pithed?
couldn't you have pithed?
couldn't she have pithed?
couldn't we have pithed?
couldn't you have pithed?
couldn't they have pithed? 	couldn't I have been pithing?
couldn't you have been pithing?
couldn't she have been pithing?
couldn't we have been pithing?
couldn't you have been pithing?
couldn't they have been pithing?