I could hollow you could hollow she could hollow we could hollow you could hollow they could hollow
V-ing form
I could be hollowing you could be hollowing she could be hollowing we could be hollowing you could be hollowing they could be hollowing
Perfect
I could have hollowed you could have hollowed she could have hollowed we could have hollowed you could have hollowed they could have hollowed
V-ing perfect
I could have been hollowing you could have been hollowing she could have been hollowing we could have been hollowing you could have been hollowing they could have been hollowing
Negation
Simple form
I couldn't hollow you couldn't hollow she couldn't hollow we couldn't hollow you couldn't hollow they couldn't hollow
V-ing form
I couldn't be hollowing you couldn't be hollowing she couldn't be hollowing we couldn't be hollowing you couldn't be hollowing they couldn't be hollowing
Perfect
I couldn't have hollowed you couldn't have hollowed she couldn't have hollowed we couldn't have hollowed you couldn't have hollowed they couldn't have hollowed
V-ing perfect
I couldn't have been hollowing you couldn't have been hollowing she couldn't have been hollowing we couldn't have been hollowing you couldn't have been hollowing they couldn't have been hollowing
Interrogative form
Simple form
could I hollow? could you hollow? could she hollow? could we hollow? could you hollow? could they hollow?
V-ing form
could I be hollowing? could you be hollowing? could she be hollowing? could we be hollowing? could you be hollowing? could they be hollowing?
Perfect
could I have hollowed? could you have hollowed? could she have hollowed? could we have hollowed? could you have hollowed? could they have hollowed?
V-ing perfect
could I have been hollowing? could you have been hollowing? could she have been hollowing? could we have been hollowing? could you have been hollowing? could they have been hollowing?
Interro-negative form
Simple form
couldn't I hollow? couldn't you hollow? couldn't she hollow? couldn't we hollow? couldn't you hollow? couldn't they hollow?
V-ing form
couldn't I be hollowing? couldn't you be hollowing? couldn't she be hollowing? couldn't we be hollowing? couldn't you be hollowing? couldn't they be hollowing?
Perfect
couldn't I have hollowed? couldn't you have hollowed? couldn't she have hollowed? couldn't we have hollowed? couldn't you have hollowed? couldn't they have hollowed?
V-ing perfect
couldn't I have been hollowing? couldn't you have been hollowing? couldn't she have been hollowing? couldn't we have been hollowing? couldn't you have been hollowing? couldn't they have been hollowing?