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 couldn't etch you couldn't etch she couldn't etch we couldn't etch you couldn't etch they couldn't etch
V-ing form
I couldn't be etching you couldn't be etching she couldn't be etching we couldn't be etching you couldn't be etching they couldn't be etching
Perfect
I couldn't have etched you couldn't have etched she couldn't have etched we couldn't have etched you couldn't have etched they couldn't have etched
V-ing perfect
I couldn't have been etching you couldn't have been etching she couldn't have been etching we couldn't have been etching you couldn't have been etching they couldn't 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
couldn't I etch? couldn't you etch? couldn't she etch? couldn't we etch? couldn't you etch? couldn't they etch?
V-ing form
couldn't I be etching? couldn't you be etching? couldn't she be etching? couldn't we be etching? couldn't you be etching? couldn't they be etching?
Perfect
couldn't I have etched? couldn't you have etched? couldn't she have etched? couldn't we have etched? couldn't you have etched? couldn't they have etched?
V-ing perfect
couldn't I have been etching? couldn't you have been etching? couldn't she have been etching? couldn't we have been etching? couldn't you have been etching? couldn't they have been etching?