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