I can perch you can perch he can perch we can perch you can perch they can perch
V-ing form
I can be perching you can be perching he can be perching we can be perching you can be perching they can be perching
Perfect
I can have perched you can have perched he can have perched we can have perched you can have perched they can have perched
V-ing perfect
I can have been perching you can have been perching he can have been perching we can have been perching you can have been perching they can have been perching
Negation
Simple form
I can't perch you can't perch he can't perch we can't perch you can't perch they can't perch
V-ing form
I can't be perching you can't be perching he can't be perching we can't be perching you can't be perching they can't be perching
Perfect
I can't have perched you can't have perched he can't have perched we can't have perched you can't have perched they can't have perched
V-ing perfect
I can't have been perching you can't have been perching he can't have been perching we can't have been perching you can't have been perching they can't have been perching
Interrogative form
Simple form
can I perch? can you perch? can he perch? can we perch? can you perch? can they perch?
V-ing form
can I be perching? can you be perching? can he be perching? can we be perching? can you be perching? can they be perching?
Perfect
can I have perched? can you have perched? can he have perched? can we have perched? can you have perched? can they have perched?
V-ing perfect
can I have been perching? can you have been perching? can he have been perching? can we have been perching? can you have been perching? can they have been perching?
Interro-negative form
Simple form
can't I perch? can't you perch? can't he perch? can't we perch? can't you perch? can't they perch?
V-ing form
can't I be perching? can't you be perching? can't he be perching? can't we be perching? can't you be perching? can't they be perching?
Perfect
can't I have perched? can't you have perched? can't he have perched? can't we have perched? can't you have perched? can't they have perched?
V-ing perfect
can't I have been perching? can't you have been perching? can't he have been perching? can't we have been perching? can't you have been perching? can't they have been perching?