I could sunbathe you could sunbathe she could sunbathe we could sunbathe you could sunbathe they could sunbathe
V-ing form
I could be sunbathing you could be sunbathing she could be sunbathing we could be sunbathing you could be sunbathing they could be sunbathing
Perfect
I could have sunbathed you could have sunbathed she could have sunbathed we could have sunbathed you could have sunbathed they could have sunbathed
V-ing perfect
I could have been sunbathing you could have been sunbathing she could have been sunbathing we could have been sunbathing you could have been sunbathing they could have been sunbathing
Negation
Simple form
I could not sunbathe you could not sunbathe she could not sunbathe we could not sunbathe you could not sunbathe they could not sunbathe
V-ing form
I could not be sunbathing you could not be sunbathing she could not be sunbathing we could not be sunbathing you could not be sunbathing they could not be sunbathing
Perfect
I could not have sunbathed you could not have sunbathed she could not have sunbathed we could not have sunbathed you could not have sunbathed they could not have sunbathed
V-ing perfect
I could not have been sunbathing you could not have been sunbathing she could not have been sunbathing we could not have been sunbathing you could not have been sunbathing they could not have been sunbathing
Interrogative form
Simple form
could I sunbathe? could you sunbathe? could she sunbathe? could we sunbathe? could you sunbathe? could they sunbathe?
V-ing form
could I be sunbathing? could you be sunbathing? could she be sunbathing? could we be sunbathing? could you be sunbathing? could they be sunbathing?
Perfect
could I have sunbathed? could you have sunbathed? could she have sunbathed? could we have sunbathed? could you have sunbathed? could they have sunbathed?
V-ing perfect
could I have been sunbathing? could you have been sunbathing? could she have been sunbathing? could we have been sunbathing? could you have been sunbathing? could they have been sunbathing?
Interro-negative form
Simple form
could I not sunbathe? could you not sunbathe? could she not sunbathe? could we not sunbathe? could you not sunbathe? could they not sunbathe?
V-ing form
could I not be sunbathing? could you not be sunbathing? could she not be sunbathing? could we not be sunbathing? could you not be sunbathing? could they not be sunbathing?
Perfect
could I not have sunbathed? could you not have sunbathed? could she not have sunbathed? could we not have sunbathed? could you not have sunbathed? could they not have sunbathed?
V-ing perfect
could I not have been sunbathing? could you not have been sunbathing? could she not have been sunbathing? could we not have been sunbathing? could you not have been sunbathing? could they not have been sunbathing?