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