I could etch you could etch she could etch we could etch you could etch they could etch
V-ing form
I could be etching you could be etching she could be etching we could be etching you could be etching they could be etching
Perfect
I could have etched you could have etched she could have etched we could have etched you could have etched they could have etched
V-ing perfect
I could have been etching you could have been etching she could have been etching we could have been etching you could have been etching they could have been etching
Negation
Simple form
I could not etch you could not etch she could not etch we could not etch you could not etch they could not etch
V-ing form
I could not be etching you could not be etching she could not be etching we could not be etching you could not be etching they could not be etching
Perfect
I could not have etched you could not have etched she could not have etched we could not have etched you could not have etched they could not have etched
V-ing perfect
I could not have been etching you could not have been etching she could not have been etching we could not have been etching you could not have been etching they could not have been etching
Interrogative form
Simple form
could I etch? could you etch? could she etch? could we etch? could you etch? could they etch?
V-ing form
could I be etching? could you be etching? could she be etching? could we be etching? could you be etching? could they be etching?
Perfect
could I have etched? could you have etched? could she have etched? could we have etched? could you have etched? could they have etched?
V-ing perfect
could I have been etching? could you have been etching? could she have been etching? could we have been etching? could you have been etching? could they have been etching?
Interro-negative form
Simple form
could I not etch? could you not etch? could she not etch? could we not etch? could you not etch? could they not etch?
V-ing form
could I not be etching? could you not be etching? could she not be etching? could we not be etching? could you not be etching? could they not be etching?
Perfect
could I not have etched? could you not have etched? could she not have etched? could we not have etched? could you not have etched? could they not have etched?
V-ing perfect
could I not have been etching? could you not have been etching? could she not have been etching? could we not have been etching? could you not have been etching? could they not have been etching?