I can double you can double she can double we can double you can double they can double
V-ing form
I can be doubling you can be doubling she can be doubling we can be doubling you can be doubling they can be doubling
Perfect
I can have doubled you can have doubled she can have doubled we can have doubled you can have doubled they can have doubled
V-ing perfect
I can have been doubling you can have been doubling she can have been doubling we can have been doubling you can have been doubling they can have been doubling
Negation
Simple form
I cannot double you cannot double she cannot double we cannot double you cannot double they cannot double
V-ing form
I cannot be doubling you cannot be doubling she cannot be doubling we cannot be doubling you cannot be doubling they cannot be doubling
Perfect
I cannot have doubled you cannot have doubled she cannot have doubled we cannot have doubled you cannot have doubled they cannot have doubled
V-ing perfect
I cannot have been doubling you cannot have been doubling she cannot have been doubling we cannot have been doubling you cannot have been doubling they cannot have been doubling
Interrogative form
Simple form
can I double? can you double? can she double? can we double? can you double? can they double?
V-ing form
can I be doubling? can you be doubling? can she be doubling? can we be doubling? can you be doubling? can they be doubling?
Perfect
can I have doubled? can you have doubled? can she have doubled? can we have doubled? can you have doubled? can they have doubled?
V-ing perfect
can I have been doubling? can you have been doubling? can she have been doubling? can we have been doubling? can you have been doubling? can they have been doubling?
Interro-negative form
Simple form
can I not double? can you not double? can she not double? can we not double? can you not double? can they not double?
V-ing form
can I not be doubling? can you not be doubling? can she not be doubling? can we not be doubling? can you not be doubling? can they not be doubling?
Perfect
can I not have doubled? can you not have doubled? can she not have doubled? can we not have doubled? can you not have doubled? can they not have doubled?
V-ing perfect
can I not have been doubling? can you not have been doubling? can she not have been doubling? can we not have been doubling? can you not have been doubling? can they not have been doubling?