I can open you can open she can open we can open you can open they can open
V-ing form
I can be opening you can be opening she can be opening we can be opening you can be opening they can be opening
Perfect
I can have opened you can have opened she can have opened we can have opened you can have opened they can have opened
V-ing perfect
I can have been opening you can have been opening she can have been opening we can have been opening you can have been opening they can have been opening
Negation
Simple form
I can't open you can't open she can't open we can't open you can't open they can't open
V-ing form
I can't be opening you can't be opening she can't be opening we can't be opening you can't be opening they can't be opening
Perfect
I can't have opened you can't have opened she can't have opened we can't have opened you can't have opened they can't have opened
V-ing perfect
I can't have been opening you can't have been opening she can't have been opening we can't have been opening you can't have been opening they can't have been opening
Interrogative form
Simple form
can I open? can you open? can she open? can we open? can you open? can they open?
V-ing form
can I be opening? can you be opening? can she be opening? can we be opening? can you be opening? can they be opening?
Perfect
can I have opened? can you have opened? can she have opened? can we have opened? can you have opened? can they have opened?
V-ing perfect
can I have been opening? can you have been opening? can she have been opening? can we have been opening? can you have been opening? can they have been opening?
Interro-negative form
Simple form
can't I open? can't you open? can't she open? can't we open? can't you open? can't they open?
V-ing form
can't I be opening? can't you be opening? can't she be opening? can't we be opening? can't you be opening? can't they be opening?
Perfect
can't I have opened? can't you have opened? can't she have opened? can't we have opened? can't you have opened? can't they have opened?
V-ing perfect
can't I have been opening? can't you have been opening? can't she have been opening? can't we have been opening? can't you have been opening? can't they have been opening?