can add
Regular verb: add - added- added

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can add
you can add
he can add
we can add
you can add
they can add 	I can be adding
you can be adding
he can be adding
we can be adding
you can be adding
they can be adding	I can have added
you can have added
he can have added
we can have added
you can have added
they can have added	I can have been adding
you can have been adding
he can have been adding
we can have been adding
you can have been adding
they can have been adding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot add
you cannot add
he cannot add
we cannot add
you cannot add
they cannot add 	I cannot be adding
you cannot be adding
he cannot be adding
we cannot be adding
you cannot be adding
they cannot be adding	I cannot have added
you cannot have added
he cannot have added
we cannot have added
you cannot have added
they cannot have added	I cannot have been adding
you cannot have been adding
he cannot have been adding
we cannot have been adding
you cannot have been adding
they cannot have been adding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I add?
can you add?
can he add?
can we add?
can you add?
can they add? 	can I be adding?
can you be adding?
can he be adding?
can we be adding?
can you be adding?
can they be adding? 	can I have added?
can you have added?
can he have added?
can we have added?
can you have added?
can they have added? 	can I have been adding?
can you have been adding?
can he have been adding?
can we have been adding?
can you have been adding?
can they have been adding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not add?
can you not add?
can he not add?
can we not add?
can you not add?
can they not add? 	can I not be adding?
can you not be adding?
can he not be adding?
can we not be adding?
can you not be adding?
can they not be adding? 	can I not have added?
can you not have added?
can he not have added?
can we not have added?
can you not have added?
can they not have added? 	can I not have been adding?
can you not have been adding?
can he not have been adding?
can we not have been adding?
can you not have been adding?
can they not have been adding?