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 couldn't arch you couldn't arch he couldn't arch we couldn't arch you couldn't arch they couldn't arch	I couldn't be arching you couldn't be arching he couldn't be arching we couldn't be arching you couldn't be arching they couldn't be arching
Perfect	V-ing perfect
I couldn't have arched you couldn't have arched he couldn't have arched we couldn't have arched you couldn't have arched they couldn't have arched	I couldn't have been arching you couldn't have been arching he couldn't have been arching we couldn't have been arching you couldn't have been arching they couldn't 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
couldn't I arch? couldn't you arch? couldn't he arch? couldn't we arch? couldn't you arch? couldn't they arch?	couldn't I be arching? couldn't you be arching? couldn't he be arching? couldn't we be arching? couldn't you be arching? couldn't they be arching?
Perfect	V-ing perfect
couldn't I have arched? couldn't you have arched? couldn't he have arched? couldn't we have arched? couldn't you have arched? couldn't they have arched?	couldn't I have been arching? couldn't you have been arching? couldn't he have been arching? couldn't we have been arching? couldn't you have been arching? couldn't they have been arching?