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