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 cannot concertise you cannot concertise he cannot concertise we cannot concertise you cannot concertise they cannot concertise
V-ing form
I cannot be concertising you cannot be concertising he cannot be concertising we cannot be concertising you cannot be concertising they cannot be concertising
Perfect
I cannot have concertised you cannot have concertised he cannot have concertised we cannot have concertised you cannot have concertised they cannot have concertised
V-ing perfect
I cannot have been concertising you cannot have been concertising he cannot have been concertising we cannot have been concertising you cannot have been concertising they cannot 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 I not concertise? can you not concertise? can he not concertise? can we not concertise? can you not concertise? can they not concertise?
V-ing form
can I not be concertising? can you not be concertising? can he not be concertising? can we not be concertising? can you not be concertising? can they not be concertising?
Perfect
can I not have concertised? can you not have concertised? can he not have concertised? can we not have concertised? can you not have concertised? can they not have concertised?
V-ing perfect
can I not have been concertising? can you not have been concertising? can he not have been concertising? can we not have been concertising? can you not have been concertising? can they not have been concertising?