I can flag you can flag he can flag we can flag you can flag they can flag
V-ing form
I can be flagging you can be flagging he can be flagging we can be flagging you can be flagging they can be flagging
Perfect
I can have flagged you can have flagged he can have flagged we can have flagged you can have flagged they can have flagged
V-ing perfect
I can have been flagging you can have been flagging he can have been flagging we can have been flagging you can have been flagging they can have been flagging
Negation
Simple form
I can't flag you can't flag he can't flag we can't flag you can't flag they can't flag
V-ing form
I can't be flagging you can't be flagging he can't be flagging we can't be flagging you can't be flagging they can't be flagging
Perfect
I can't have flagged you can't have flagged he can't have flagged we can't have flagged you can't have flagged they can't have flagged
V-ing perfect
I can't have been flagging you can't have been flagging he can't have been flagging we can't have been flagging you can't have been flagging they can't have been flagging
Interrogative form
Simple form
can I flag? can you flag? can he flag? can we flag? can you flag? can they flag?
V-ing form
can I be flagging? can you be flagging? can he be flagging? can we be flagging? can you be flagging? can they be flagging?
Perfect
can I have flagged? can you have flagged? can he have flagged? can we have flagged? can you have flagged? can they have flagged?
V-ing perfect
can I have been flagging? can you have been flagging? can he have been flagging? can we have been flagging? can you have been flagging? can they have been flagging?
Interro-negative form
Simple form
can't I flag? can't you flag? can't he flag? can't we flag? can't you flag? can't they flag?
V-ing form
can't I be flagging? can't you be flagging? can't he be flagging? can't we be flagging? can't you be flagging? can't they be flagging?
Perfect
can't I have flagged? can't you have flagged? can't he have flagged? can't we have flagged? can't you have flagged? can't they have flagged?
V-ing perfect
can't I have been flagging? can't you have been flagging? can't he have been flagging? can't we have been flagging? can't you have been flagging? can't they have been flagging?