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