I could arm you could arm he could arm we could arm you could arm they could arm
V-ing form
I could be arming you could be arming he could be arming we could be arming you could be arming they could be arming
Perfect
I could have armed you could have armed he 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 he 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 he 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 he 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 he 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 he 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 he arm? could we arm? could you arm? could they arm?
V-ing form
could I be arming? could you be arming? could he be arming? could we be arming? could you be arming? could they be arming?
Perfect
could I have armed? could you have armed? could he 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 he 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 he 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 he 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 he 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 he have been arming? couldn't we have been arming? couldn't you have been arming? couldn't they have been arming?