I can touch you can touch she can touch we can touch you can touch they can touch
V-ing form
I can be touching you can be touching she can be touching we can be touching you can be touching they can be touching
Perfect
I can have touched you can have touched she can have touched we can have touched you can have touched they can have touched
V-ing perfect
I can have been touching you can have been touching she can have been touching we can have been touching you can have been touching they can have been touching
Negation
Simple form
I can't touch you can't touch she can't touch we can't touch you can't touch they can't touch
V-ing form
I can't be touching you can't be touching she can't be touching we can't be touching you can't be touching they can't be touching
Perfect
I can't have touched you can't have touched she can't have touched we can't have touched you can't have touched they can't have touched
V-ing perfect
I can't have been touching you can't have been touching she can't have been touching we can't have been touching you can't have been touching they can't have been touching
Interrogative form
Simple form
can I touch? can you touch? can she touch? can we touch? can you touch? can they touch?
V-ing form
can I be touching? can you be touching? can she be touching? can we be touching? can you be touching? can they be touching?
Perfect
can I have touched? can you have touched? can she have touched? can we have touched? can you have touched? can they have touched?
V-ing perfect
can I have been touching? can you have been touching? can she have been touching? can we have been touching? can you have been touching? can they have been touching?
Interro-negative form
Simple form
can't I touch? can't you touch? can't she touch? can't we touch? can't you touch? can't they touch?
V-ing form
can't I be touching? can't you be touching? can't she be touching? can't we be touching? can't you be touching? can't they be touching?
Perfect
can't I have touched? can't you have touched? can't she have touched? can't we have touched? can't you have touched? can't they have touched?
V-ing perfect
can't I have been touching? can't you have been touching? can't she have been touching? can't we have been touching? can't you have been touching? can't they have been touching?