I could mercerise you could mercerise she could mercerise we could mercerise you could mercerise they could mercerise
V-ing form
I could be mercerising you could be mercerising she could be mercerising we could be mercerising you could be mercerising they could be mercerising
Perfect
I could have mercerised you could have mercerised she could have mercerised we could have mercerised you could have mercerised they could have mercerised
V-ing perfect
I could have been mercerising you could have been mercerising she could have been mercerising we could have been mercerising you could have been mercerising they could have been mercerising
Negation
Simple form
I could not mercerise you could not mercerise she could not mercerise we could not mercerise you could not mercerise they could not mercerise
V-ing form
I could not be mercerising you could not be mercerising she could not be mercerising we could not be mercerising you could not be mercerising they could not be mercerising
Perfect
I could not have mercerised you could not have mercerised she could not have mercerised we could not have mercerised you could not have mercerised they could not have mercerised
V-ing perfect
I could not have been mercerising you could not have been mercerising she could not have been mercerising we could not have been mercerising you could not have been mercerising they could not have been mercerising
Interrogative form
Simple form
could I mercerise? could you mercerise? could she mercerise? could we mercerise? could you mercerise? could they mercerise?
V-ing form
could I be mercerising? could you be mercerising? could she be mercerising? could we be mercerising? could you be mercerising? could they be mercerising?
Perfect
could I have mercerised? could you have mercerised? could she have mercerised? could we have mercerised? could you have mercerised? could they have mercerised?
V-ing perfect
could I have been mercerising? could you have been mercerising? could she have been mercerising? could we have been mercerising? could you have been mercerising? could they have been mercerising?
Interro-negative form
Simple form
could I not mercerise? could you not mercerise? could she not mercerise? could we not mercerise? could you not mercerise? could they not mercerise?
V-ing form
could I not be mercerising? could you not be mercerising? could she not be mercerising? could we not be mercerising? could you not be mercerising? could they not be mercerising?
Perfect
could I not have mercerised? could you not have mercerised? could she not have mercerised? could we not have mercerised? could you not have mercerised? could they not have mercerised?
V-ing perfect
could I not have been mercerising? could you not have been mercerising? could she not have been mercerising? could we not have been mercerising? could you not have been mercerising? could they not have been mercerising?