I could mercerise you could mercerise he could mercerise we could mercerise you could mercerise they could mercerise
V-ing form
I could be mercerising you could be mercerising he could be mercerising we could be mercerising you could be mercerising they could be mercerising
Perfect
I could have mercerised you could have mercerised he 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 he 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 he 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 he 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 he 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 he 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 he mercerise? could we mercerise? could you mercerise? could they mercerise?
V-ing form
could I be mercerising? could you be mercerising? could he be mercerising? could we be mercerising? could you be mercerising? could they be mercerising?
Perfect
could I have mercerised? could you have mercerised? could he 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 he 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 he 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 he 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 he 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 he not have been mercerising? could we not have been mercerising? could you not have been mercerising? could they not have been mercerising?