I can protect you can protect he can protect we can protect you can protect they can protect
V-ing form
I can be protecting you can be protecting he can be protecting we can be protecting you can be protecting they can be protecting
Perfect
I can have protected you can have protected he can have protected we can have protected you can have protected they can have protected
V-ing perfect
I can have been protecting you can have been protecting he can have been protecting we can have been protecting you can have been protecting they can have been protecting
Negation
Simple form
I can't protect you can't protect he can't protect we can't protect you can't protect they can't protect
V-ing form
I can't be protecting you can't be protecting he can't be protecting we can't be protecting you can't be protecting they can't be protecting
Perfect
I can't have protected you can't have protected he can't have protected we can't have protected you can't have protected they can't have protected
V-ing perfect
I can't have been protecting you can't have been protecting he can't have been protecting we can't have been protecting you can't have been protecting they can't have been protecting
Interrogative form
Simple form
can I protect? can you protect? can he protect? can we protect? can you protect? can they protect?
V-ing form
can I be protecting? can you be protecting? can he be protecting? can we be protecting? can you be protecting? can they be protecting?
Perfect
can I have protected? can you have protected? can he have protected? can we have protected? can you have protected? can they have protected?
V-ing perfect
can I have been protecting? can you have been protecting? can he have been protecting? can we have been protecting? can you have been protecting? can they have been protecting?
Interro-negative form
Simple form
can't I protect? can't you protect? can't he protect? can't we protect? can't you protect? can't they protect?
V-ing form
can't I be protecting? can't you be protecting? can't he be protecting? can't we be protecting? can't you be protecting? can't they be protecting?
Perfect
can't I have protected? can't you have protected? can't he have protected? can't we have protected? can't you have protected? can't they have protected?
V-ing perfect
can't I have been protecting? can't you have been protecting? can't he have been protecting? can't we have been protecting? can't you have been protecting? can't they have been protecting?