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