I could prelude you could prelude he could prelude we could prelude you could prelude they could prelude
V-ing form
I could be preluding you could be preluding he could be preluding we could be preluding you could be preluding they could be preluding
Perfect
I could have preluded you could have preluded he could have preluded we could have preluded you could have preluded they could have preluded
V-ing perfect
I could have been preluding you could have been preluding he could have been preluding we could have been preluding you could have been preluding they could have been preluding
Negation
Simple form
I could not prelude you could not prelude he could not prelude we could not prelude you could not prelude they could not prelude
V-ing form
I could not be preluding you could not be preluding he could not be preluding we could not be preluding you could not be preluding they could not be preluding
Perfect
I could not have preluded you could not have preluded he could not have preluded we could not have preluded you could not have preluded they could not have preluded
V-ing perfect
I could not have been preluding you could not have been preluding he could not have been preluding we could not have been preluding you could not have been preluding they could not have been preluding
Interrogative form
Simple form
could I prelude? could you prelude? could he prelude? could we prelude? could you prelude? could they prelude?
V-ing form
could I be preluding? could you be preluding? could he be preluding? could we be preluding? could you be preluding? could they be preluding?
Perfect
could I have preluded? could you have preluded? could he have preluded? could we have preluded? could you have preluded? could they have preluded?
V-ing perfect
could I have been preluding? could you have been preluding? could he have been preluding? could we have been preluding? could you have been preluding? could they have been preluding?
Interro-negative form
Simple form
could I not prelude? could you not prelude? could he not prelude? could we not prelude? could you not prelude? could they not prelude?
V-ing form
could I not be preluding? could you not be preluding? could he not be preluding? could we not be preluding? could you not be preluding? could they not be preluding?
Perfect
could I not have preluded? could you not have preluded? could he not have preluded? could we not have preluded? could you not have preluded? could they not have preluded?
V-ing perfect
could I not have been preluding? could you not have been preluding? could he not have been preluding? could we not have been preluding? could you not have been preluding? could they not have been preluding?