I can concertise you can concertise he can concertise we can concertise you can concertise they can concertise
V-ing form
I can be concertising you can be concertising he can be concertising we can be concertising you can be concertising they can be concertising
Perfect
I can have concertised you can have concertised he can have concertised we can have concertised you can have concertised they can have concertised
V-ing perfect
I can have been concertising you can have been concertising he can have been concertising we can have been concertising you can have been concertising they can have been concertising
Negation
Simple form
I can't concertise you can't concertise he can't concertise we can't concertise you can't concertise they can't concertise
V-ing form
I can't be concertising you can't be concertising he can't be concertising we can't be concertising you can't be concertising they can't be concertising
Perfect
I can't have concertised you can't have concertised he can't have concertised we can't have concertised you can't have concertised they can't have concertised
V-ing perfect
I can't have been concertising you can't have been concertising he can't have been concertising we can't have been concertising you can't have been concertising they can't have been concertising
Interrogative form
Simple form
can I concertise? can you concertise? can he concertise? can we concertise? can you concertise? can they concertise?
V-ing form
can I be concertising? can you be concertising? can he be concertising? can we be concertising? can you be concertising? can they be concertising?
Perfect
can I have concertised? can you have concertised? can he have concertised? can we have concertised? can you have concertised? can they have concertised?
V-ing perfect
can I have been concertising? can you have been concertising? can he have been concertising? can we have been concertising? can you have been concertising? can they have been concertising?
Interro-negative form
Simple form
can't I concertise? can't you concertise? can't he concertise? can't we concertise? can't you concertise? can't they concertise?
V-ing form
can't I be concertising? can't you be concertising? can't he be concertising? can't we be concertising? can't you be concertising? can't they be concertising?
Perfect
can't I have concertised? can't you have concertised? can't he have concertised? can't we have concertised? can't you have concertised? can't they have concertised?
V-ing perfect
can't I have been concertising? can't you have been concertising? can't he have been concertising? can't we have been concertising? can't you have been concertising? can't they have been concertising?