can intervene
Regular verb: intervene - intervened- intervened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can intervene
you can intervene
he can intervene
we can intervene
you can intervene
they can intervene 	I can be intervening
you can be intervening
he can be intervening
we can be intervening
you can be intervening
they can be intervening	I can have intervened
you can have intervened
he can have intervened
we can have intervened
you can have intervened
they can have intervened	I can have been intervening
you can have been intervening
he can have been intervening
we can have been intervening
you can have been intervening
they can have been intervening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't intervene
you can't intervene
he can't intervene
we can't intervene
you can't intervene
they can't intervene 	I can't be intervening
you can't be intervening
he can't be intervening
we can't be intervening
you can't be intervening
they can't be intervening	I can't have intervened
you can't have intervened
he can't have intervened
we can't have intervened
you can't have intervened
they can't have intervened	I can't have been intervening
you can't have been intervening
he can't have been intervening
we can't have been intervening
you can't have been intervening
they can't have been intervening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I intervene?
can you intervene?
can he intervene?
can we intervene?
can you intervene?
can they intervene? 	can I be intervening?
can you be intervening?
can he be intervening?
can we be intervening?
can you be intervening?
can they be intervening? 	can I have intervened?
can you have intervened?
can he have intervened?
can we have intervened?
can you have intervened?
can they have intervened? 	can I have been intervening?
can you have been intervening?
can he have been intervening?
can we have been intervening?
can you have been intervening?
can they have been intervening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I intervene?
can't you intervene?
can't he intervene?
can't we intervene?
can't you intervene?
can't they intervene? 	can't I be intervening?
can't you be intervening?
can't he be intervening?
can't we be intervening?
can't you be intervening?
can't they be intervening? 	can't I have intervened?
can't you have intervened?
can't he have intervened?
can't we have intervened?
can't you have intervened?
can't they have intervened? 	can't I have been intervening?
can't you have been intervening?
can't he have been intervening?
can't we have been intervening?
can't you have been intervening?
can't they have been intervening?