I could glad you could glad he could glad we could glad you could glad they could glad
V-ing form
I could be glading you could be glading he could be glading we could be glading you could be glading they could be glading
Perfect
I could have gladed you could have gladed he could have gladed we could have gladed you could have gladed they could have gladed
V-ing perfect
I could have been glading you could have been glading he could have been glading we could have been glading you could have been glading they could have been glading
Negation
Simple form
I couldn't glad you couldn't glad he couldn't glad we couldn't glad you couldn't glad they couldn't glad
V-ing form
I couldn't be glading you couldn't be glading he couldn't be glading we couldn't be glading you couldn't be glading they couldn't be glading
Perfect
I couldn't have gladed you couldn't have gladed he couldn't have gladed we couldn't have gladed you couldn't have gladed they couldn't have gladed
V-ing perfect
I couldn't have been glading you couldn't have been glading he couldn't have been glading we couldn't have been glading you couldn't have been glading they couldn't have been glading
Interrogative form
Simple form
could I glad? could you glad? could he glad? could we glad? could you glad? could they glad?
V-ing form
could I be glading? could you be glading? could he be glading? could we be glading? could you be glading? could they be glading?
Perfect
could I have gladed? could you have gladed? could he have gladed? could we have gladed? could you have gladed? could they have gladed?
V-ing perfect
could I have been glading? could you have been glading? could he have been glading? could we have been glading? could you have been glading? could they have been glading?
Interro-negative form
Simple form
couldn't I glad? couldn't you glad? couldn't he glad? couldn't we glad? couldn't you glad? couldn't they glad?
V-ing form
couldn't I be glading? couldn't you be glading? couldn't he be glading? couldn't we be glading? couldn't you be glading? couldn't they be glading?
Perfect
couldn't I have gladed? couldn't you have gladed? couldn't he have gladed? couldn't we have gladed? couldn't you have gladed? couldn't they have gladed?
V-ing perfect
couldn't I have been glading? couldn't you have been glading? couldn't he have been glading? couldn't we have been glading? couldn't you have been glading? couldn't they have been glading?