I could melt you could melt she could melt we could melt you could melt they could melt
V-ing form
I could be melting you could be melting she could be melting we could be melting you could be melting they could be melting
Perfect
I could have melted you could have melted she could have melted we could have melted you could have melted they could have melted
V-ing perfect
I could have been melting you could have been melting she could have been melting we could have been melting you could have been melting they could have been melting
Negation
Simple form
I could not melt you could not melt she could not melt we could not melt you could not melt they could not melt
V-ing form
I could not be melting you could not be melting she could not be melting we could not be melting you could not be melting they could not be melting
Perfect
I could not have melted you could not have melted she could not have melted we could not have melted you could not have melted they could not have melted
V-ing perfect
I could not have been melting you could not have been melting she could not have been melting we could not have been melting you could not have been melting they could not have been melting
Interrogative form
Simple form
could I melt? could you melt? could she melt? could we melt? could you melt? could they melt?
V-ing form
could I be melting? could you be melting? could she be melting? could we be melting? could you be melting? could they be melting?
Perfect
could I have melted? could you have melted? could she have melted? could we have melted? could you have melted? could they have melted?
V-ing perfect
could I have been melting? could you have been melting? could she have been melting? could we have been melting? could you have been melting? could they have been melting?
Interro-negative form
Simple form
could I not melt? could you not melt? could she not melt? could we not melt? could you not melt? could they not melt?
V-ing form
could I not be melting? could you not be melting? could she not be melting? could we not be melting? could you not be melting? could they not be melting?
Perfect
could I not have melted? could you not have melted? could she not have melted? could we not have melted? could you not have melted? could they not have melted?
V-ing perfect
could I not have been melting? could you not have been melting? could she not have been melting? could we not have been melting? could you not have been melting? could they not have been melting?