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 can't concertina you can't concertina he can't concertina we can't concertina you can't concertina they can't concertina	I can't be concertinaing you can't be concertinaing he can't be concertinaing we can't be concertinaing you can't be concertinaing they can't be concertinaing
Perfect	V-ing perfect
I can't have concertinaed you can't have concertinaed he can't have concertinaed we can't have concertinaed you can't have concertinaed they can't have concertinaed	I can't have been concertinaing you can't have been concertinaing he can't have been concertinaing we can't have been concertinaing you can't have been concertinaing they can't 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't I concertina? can't you concertina? can't he concertina? can't we concertina? can't you concertina? can't they concertina?	can't I be concertinaing? can't you be concertinaing? can't he be concertinaing? can't we be concertinaing? can't you be concertinaing? can't they be concertinaing?
Perfect	V-ing perfect
can't I have concertinaed? can't you have concertinaed? can't he have concertinaed? can't we have concertinaed? can't you have concertinaed? can't they have concertinaed?	can't I have been concertinaing? can't you have been concertinaing? can't he have been concertinaing? can't we have been concertinaing? can't you have been concertinaing? can't they have been concertinaing?