I can help you can help he can help we can help you can help they can help
V-ing form
I can be helping you can be helping he can be helping we can be helping you can be helping they can be helping
Perfect
I can have helped you can have helped he can have helped we can have helped you can have helped they can have helped
V-ing perfect
I can have been helping you can have been helping he can have been helping we can have been helping you can have been helping they can have been helping
Negation
Simple form
I can't help you can't help he can't help we can't help you can't help they can't help
V-ing form
I can't be helping you can't be helping he can't be helping we can't be helping you can't be helping they can't be helping
Perfect
I can't have helped you can't have helped he can't have helped we can't have helped you can't have helped they can't have helped
V-ing perfect
I can't have been helping you can't have been helping he can't have been helping we can't have been helping you can't have been helping they can't have been helping
Interrogative form
Simple form
can I help? can you help? can he help? can we help? can you help? can they help?
V-ing form
can I be helping? can you be helping? can he be helping? can we be helping? can you be helping? can they be helping?
Perfect
can I have helped? can you have helped? can he have helped? can we have helped? can you have helped? can they have helped?
V-ing perfect
can I have been helping? can you have been helping? can he have been helping? can we have been helping? can you have been helping? can they have been helping?
Interro-negative form
Simple form
can't I help? can't you help? can't he help? can't we help? can't you help? can't they help?
V-ing form
can't I be helping? can't you be helping? can't he be helping? can't we be helping? can't you be helping? can't they be helping?
Perfect
can't I have helped? can't you have helped? can't he have helped? can't we have helped? can't you have helped? can't they have helped?
V-ing perfect
can't I have been helping? can't you have been helping? can't he have been helping? can't we have been helping? can't you have been helping? can't they have been helping?