English verb conjugation
COULD ARCH

Regular verb: arch - arched - arched

Affirmation

Simple form	V-ing form
I could arch you could arch he could arch we could arch you could arch they could arch	I could be arching you could be arching he could be arching we could be arching you could be arching they could be arching
Perfect	V-ing perfect
I could have arched you could have arched he could have arched we could have arched you could have arched they could have arched	I could have been arching you could have been arching he could have been arching we could have been arching you could have been arching they could have been arching

Negation

Simple form	V-ing form
I could not arch you could not arch he could not arch we could not arch you could not arch they could not arch	I could not be arching you could not be arching he could not be arching we could not be arching you could not be arching they could not be arching
Perfect	V-ing perfect
I could not have arched you could not have arched he could not have arched we could not have arched you could not have arched they could not have arched	I could not have been arching you could not have been arching he could not have been arching we could not have been arching you could not have been arching they could not have been arching

Interrogative form

Simple form	V-ing form
could I arch? could you arch? could he arch? could we arch? could you arch? could they arch?	could I be arching? could you be arching? could he be arching? could we be arching? could you be arching? could they be arching?
Perfect	V-ing perfect
could I have arched? could you have arched? could he have arched? could we have arched? could you have arched? could they have arched?	could I have been arching? could you have been arching? could he have been arching? could we have been arching? could you have been arching? could they have been arching?

Interro-negative form

Simple form	V-ing form
could I not arch? could you not arch? could he not arch? could we not arch? could you not arch? could they not arch?	could I not be arching? could you not be arching? could he not be arching? could we not be arching? could you not be arching? could they not be arching?
Perfect	V-ing perfect
could I not have arched? could you not have arched? could he not have arched? could we not have arched? could you not have arched? could they not have arched?	could I not have been arching? could you not have been arching? could he not have been arching? could we not have been arching? could you not have been arching? could they not have been arching?