I can counter you can counter she can counter we can counter you can counter they can counter
V-ing form
I can be countering you can be countering she can be countering we can be countering you can be countering they can be countering
Perfect
I can have countered you can have countered she can have countered we can have countered you can have countered they can have countered
V-ing perfect
I can have been countering you can have been countering she can have been countering we can have been countering you can have been countering they can have been countering
Negation
Simple form
I can't counter you can't counter she can't counter we can't counter you can't counter they can't counter
V-ing form
I can't be countering you can't be countering she can't be countering we can't be countering you can't be countering they can't be countering
Perfect
I can't have countered you can't have countered she can't have countered we can't have countered you can't have countered they can't have countered
V-ing perfect
I can't have been countering you can't have been countering she can't have been countering we can't have been countering you can't have been countering they can't have been countering
Interrogative form
Simple form
can I counter? can you counter? can she counter? can we counter? can you counter? can they counter?
V-ing form
can I be countering? can you be countering? can she be countering? can we be countering? can you be countering? can they be countering?
Perfect
can I have countered? can you have countered? can she have countered? can we have countered? can you have countered? can they have countered?
V-ing perfect
can I have been countering? can you have been countering? can she have been countering? can we have been countering? can you have been countering? can they have been countering?
Interro-negative form
Simple form
can't I counter? can't you counter? can't she counter? can't we counter? can't you counter? can't they counter?
V-ing form
can't I be countering? can't you be countering? can't she be countering? can't we be countering? can't you be countering? can't they be countering?
Perfect
can't I have countered? can't you have countered? can't she have countered? can't we have countered? can't you have countered? can't they have countered?
V-ing perfect
can't I have been countering? can't you have been countering? can't she have been countering? can't we have been countering? can't you have been countering? can't they have been countering?