could thresh
Regular verb: thresh - threshed- threshed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could thresh
you could thresh
she could thresh
we could thresh
you could thresh
they could thresh 	I could be threshing
you could be threshing
she could be threshing
we could be threshing
you could be threshing
they could be threshing	I could have threshed
you could have threshed
she could have threshed
we could have threshed
you could have threshed
they could have threshed	I could have been threshing
you could have been threshing
she could have been threshing
we could have been threshing
you could have been threshing
they could have been threshing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't thresh
you couldn't thresh
she couldn't thresh
we couldn't thresh
you couldn't thresh
they couldn't thresh 	I couldn't be threshing
you couldn't be threshing
she couldn't be threshing
we couldn't be threshing
you couldn't be threshing
they couldn't be threshing	I couldn't have threshed
you couldn't have threshed
she couldn't have threshed
we couldn't have threshed
you couldn't have threshed
they couldn't have threshed	I couldn't have been threshing
you couldn't have been threshing
she couldn't have been threshing
we couldn't have been threshing
you couldn't have been threshing
they couldn't have been threshing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I thresh?
could you thresh?
could she thresh?
could we thresh?
could you thresh?
could they thresh? 	could I be threshing?
could you be threshing?
could she be threshing?
could we be threshing?
could you be threshing?
could they be threshing? 	could I have threshed?
could you have threshed?
could she have threshed?
could we have threshed?
could you have threshed?
could they have threshed? 	could I have been threshing?
could you have been threshing?
could she have been threshing?
could we have been threshing?
could you have been threshing?
could they have been threshing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I thresh?
couldn't you thresh?
couldn't she thresh?
couldn't we thresh?
couldn't you thresh?
couldn't they thresh? 	couldn't I be threshing?
couldn't you be threshing?
couldn't she be threshing?
couldn't we be threshing?
couldn't you be threshing?
couldn't they be threshing? 	couldn't I have threshed?
couldn't you have threshed?
couldn't she have threshed?
couldn't we have threshed?
couldn't you have threshed?
couldn't they have threshed? 	couldn't I have been threshing?
couldn't you have been threshing?
couldn't she have been threshing?
couldn't we have been threshing?
couldn't you have been threshing?
couldn't they have been threshing?