English verb conjugation
CAN CONCENTER

Regular verb: concenter - concentered - concentered

Affirmation

Simple form	V-ing form
I can concenter you can concenter he can concenter we can concenter you can concenter they can concenter	I can be concentering you can be concentering he can be concentering we can be concentering you can be concentering they can be concentering
Perfect	V-ing perfect
I can have concentered you can have concentered he can have concentered we can have concentered you can have concentered they can have concentered	I can have been concentering you can have been concentering he can have been concentering we can have been concentering you can have been concentering they can have been concentering

Negation

Simple form	V-ing form
I cannot concenter you cannot concenter he cannot concenter we cannot concenter you cannot concenter they cannot concenter	I cannot be concentering you cannot be concentering he cannot be concentering we cannot be concentering you cannot be concentering they cannot be concentering
Perfect	V-ing perfect
I cannot have concentered you cannot have concentered he cannot have concentered we cannot have concentered you cannot have concentered they cannot have concentered	I cannot have been concentering you cannot have been concentering he cannot have been concentering we cannot have been concentering you cannot have been concentering they cannot have been concentering

Interrogative form

Simple form	V-ing form
can I concenter? can you concenter? can he concenter? can we concenter? can you concenter? can they concenter?	can I be concentering? can you be concentering? can he be concentering? can we be concentering? can you be concentering? can they be concentering?
Perfect	V-ing perfect
can I have concentered? can you have concentered? can he have concentered? can we have concentered? can you have concentered? can they have concentered?	can I have been concentering? can you have been concentering? can he have been concentering? can we have been concentering? can you have been concentering? can they have been concentering?

Interro-negative form

Simple form	V-ing form
can I not concenter? can you not concenter? can he not concenter? can we not concenter? can you not concenter? can they not concenter?	can I not be concentering? can you not be concentering? can he not be concentering? can we not be concentering? can you not be concentering? can they not be concentering?
Perfect	V-ing perfect
can I not have concentered? can you not have concentered? can he not have concentered? can we not have concentered? can you not have concentered? can they not have concentered?	can I not have been concentering? can you not have been concentering? can he not have been concentering? can we not have been concentering? can you not have been concentering? can they not have been concentering?