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 couldn't sunbathe you couldn't sunbathe she couldn't sunbathe we couldn't sunbathe you couldn't sunbathe they couldn't sunbathe
V-ing form
I couldn't be sunbathing you couldn't be sunbathing she couldn't be sunbathing we couldn't be sunbathing you couldn't be sunbathing they couldn't be sunbathing
Perfect
I couldn't have sunbathed you couldn't have sunbathed she couldn't have sunbathed we couldn't have sunbathed you couldn't have sunbathed they couldn't have sunbathed
V-ing perfect
I couldn't have been sunbathing you couldn't have been sunbathing she couldn't have been sunbathing we couldn't have been sunbathing you couldn't have been sunbathing they couldn't 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
couldn't I sunbathe? couldn't you sunbathe? couldn't she sunbathe? couldn't we sunbathe? couldn't you sunbathe? couldn't they sunbathe?
V-ing form
couldn't I be sunbathing? couldn't you be sunbathing? couldn't she be sunbathing? couldn't we be sunbathing? couldn't you be sunbathing? couldn't they be sunbathing?
Perfect
couldn't I have sunbathed? couldn't you have sunbathed? couldn't she have sunbathed? couldn't we have sunbathed? couldn't you have sunbathed? couldn't they have sunbathed?
V-ing perfect
couldn't I have been sunbathing? couldn't you have been sunbathing? couldn't she have been sunbathing? couldn't we have been sunbathing? couldn't you have been sunbathing? couldn't they have been sunbathing?