English verb conjugation
COULD THRESH

Regular verb: thresh - threshed - threshed

Affirmation

Simple form	V-ing form
I could thresh you could thresh he could thresh we could thresh you could thresh they could thresh	I could be threshing you could be threshing he could be threshing we could be threshing you could be threshing they could be threshing
Perfect	V-ing perfect
I could have threshed you could have threshed he 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 he 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
I could not thresh you could not thresh he could not thresh we could not thresh you could not thresh they could not thresh	I could not be threshing you could not be threshing he could not be threshing we could not be threshing you could not be threshing they could not be threshing
Perfect	V-ing perfect
I could not have threshed you could not have threshed he could not have threshed we could not have threshed you could not have threshed they could not have threshed	I could not have been threshing you could not have been threshing he could not have been threshing we could not have been threshing you could not have been threshing they could not have been threshing

Interrogative form

Simple form	V-ing form
could I thresh? could you thresh? could he thresh? could we thresh? could you thresh? could they thresh?	could I be threshing? could you be threshing? could he be threshing? could we be threshing? could you be threshing? could they be threshing?
Perfect	V-ing perfect
could I have threshed? could you have threshed? could he 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 he 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
could I not thresh? could you not thresh? could he not thresh? could we not thresh? could you not thresh? could they not thresh?	could I not be threshing? could you not be threshing? could he not be threshing? could we not be threshing? could you not be threshing? could they not be threshing?
Perfect	V-ing perfect
could I not have threshed? could you not have threshed? could he not have threshed? could we not have threshed? could you not have threshed? could they not have threshed?	could I not have been threshing? could you not have been threshing? could he not have been threshing? could we not have been threshing? could you not have been threshing? could they not have been threshing?