I could arm you could arm she could arm we could arm you could arm they could arm
V-ing form
I could be arming you could be arming she could be arming we could be arming you could be arming they could be arming
Perfect
I could have armed you could have armed she could have armed we could have armed you could have armed they could have armed
V-ing perfect
I could have been arming you could have been arming she could have been arming we could have been arming you could have been arming they could have been arming
Negation
Simple form
I couldn't arm you couldn't arm she couldn't arm we couldn't arm you couldn't arm they couldn't arm
V-ing form
I couldn't be arming you couldn't be arming she couldn't be arming we couldn't be arming you couldn't be arming they couldn't be arming
Perfect
I couldn't have armed you couldn't have armed she couldn't have armed we couldn't have armed you couldn't have armed they couldn't have armed
V-ing perfect
I couldn't have been arming you couldn't have been arming she couldn't have been arming we couldn't have been arming you couldn't have been arming they couldn't have been arming
Interrogative form
Simple form
could I arm? could you arm? could she arm? could we arm? could you arm? could they arm?
V-ing form
could I be arming? could you be arming? could she be arming? could we be arming? could you be arming? could they be arming?
Perfect
could I have armed? could you have armed? could she have armed? could we have armed? could you have armed? could they have armed?
V-ing perfect
could I have been arming? could you have been arming? could she have been arming? could we have been arming? could you have been arming? could they have been arming?
Interro-negative form
Simple form
couldn't I arm? couldn't you arm? couldn't she arm? couldn't we arm? couldn't you arm? couldn't they arm?
V-ing form
couldn't I be arming? couldn't you be arming? couldn't she be arming? couldn't we be arming? couldn't you be arming? couldn't they be arming?
Perfect
couldn't I have armed? couldn't you have armed? couldn't she have armed? couldn't we have armed? couldn't you have armed? couldn't they have armed?
V-ing perfect
couldn't I have been arming? couldn't you have been arming? couldn't she have been arming? couldn't we have been arming? couldn't you have been arming? couldn't they have been arming?