English verb conjugation
CAN CONCERTINA

Regular verb: concertina - concertinaed - concertinaed

Affirmation

Simple form	V-ing form
I can concertina you can concertina he can concertina we can concertina you can concertina they can concertina	I can be concertinaing you can be concertinaing he can be concertinaing we can be concertinaing you can be concertinaing they can be concertinaing
Perfect	V-ing perfect
I can have concertinaed you can have concertinaed he can have concertinaed we can have concertinaed you can have concertinaed they can have concertinaed	I can have been concertinaing you can have been concertinaing he can have been concertinaing we can have been concertinaing you can have been concertinaing they can have been concertinaing

Negation

Simple form	V-ing form
I cannot concertina you cannot concertina he cannot concertina we cannot concertina you cannot concertina they cannot concertina	I cannot be concertinaing you cannot be concertinaing he cannot be concertinaing we cannot be concertinaing you cannot be concertinaing they cannot be concertinaing
Perfect	V-ing perfect
I cannot have concertinaed you cannot have concertinaed he cannot have concertinaed we cannot have concertinaed you cannot have concertinaed they cannot have concertinaed	I cannot have been concertinaing you cannot have been concertinaing he cannot have been concertinaing we cannot have been concertinaing you cannot have been concertinaing they cannot have been concertinaing

Interrogative form

Simple form	V-ing form
can I concertina? can you concertina? can he concertina? can we concertina? can you concertina? can they concertina?	can I be concertinaing? can you be concertinaing? can he be concertinaing? can we be concertinaing? can you be concertinaing? can they be concertinaing?
Perfect	V-ing perfect
can I have concertinaed? can you have concertinaed? can he have concertinaed? can we have concertinaed? can you have concertinaed? can they have concertinaed?	can I have been concertinaing? can you have been concertinaing? can he have been concertinaing? can we have been concertinaing? can you have been concertinaing? can they have been concertinaing?

Interro-negative form

Simple form	V-ing form
can I not concertina? can you not concertina? can he not concertina? can we not concertina? can you not concertina? can they not concertina?	can I not be concertinaing? can you not be concertinaing? can he not be concertinaing? can we not be concertinaing? can you not be concertinaing? can they not be concertinaing?
Perfect	V-ing perfect
can I not have concertinaed? can you not have concertinaed? can he not have concertinaed? can we not have concertinaed? can you not have concertinaed? can they not have concertinaed?	can I not have been concertinaing? can you not have been concertinaing? can he not have been concertinaing? can we not have been concertinaing? can you not have been concertinaing? can they not have been concertinaing?