I can yelp you can yelp she can yelp we can yelp you can yelp they can yelp
V-ing form
I can be yelping you can be yelping she can be yelping we can be yelping you can be yelping they can be yelping
Perfect
I can have yelped you can have yelped she can have yelped we can have yelped you can have yelped they can have yelped
V-ing perfect
I can have been yelping you can have been yelping she can have been yelping we can have been yelping you can have been yelping they can have been yelping
Negation
Simple form
I cannot yelp you cannot yelp she cannot yelp we cannot yelp you cannot yelp they cannot yelp
V-ing form
I cannot be yelping you cannot be yelping she cannot be yelping we cannot be yelping you cannot be yelping they cannot be yelping
Perfect
I cannot have yelped you cannot have yelped she cannot have yelped we cannot have yelped you cannot have yelped they cannot have yelped
V-ing perfect
I cannot have been yelping you cannot have been yelping she cannot have been yelping we cannot have been yelping you cannot have been yelping they cannot have been yelping
Interrogative form
Simple form
can I yelp? can you yelp? can she yelp? can we yelp? can you yelp? can they yelp?
V-ing form
can I be yelping? can you be yelping? can she be yelping? can we be yelping? can you be yelping? can they be yelping?
Perfect
can I have yelped? can you have yelped? can she have yelped? can we have yelped? can you have yelped? can they have yelped?
V-ing perfect
can I have been yelping? can you have been yelping? can she have been yelping? can we have been yelping? can you have been yelping? can they have been yelping?
Interro-negative form
Simple form
can I not yelp? can you not yelp? can she not yelp? can we not yelp? can you not yelp? can they not yelp?
V-ing form
can I not be yelping? can you not be yelping? can she not be yelping? can we not be yelping? can you not be yelping? can they not be yelping?
Perfect
can I not have yelped? can you not have yelped? can she not have yelped? can we not have yelped? can you not have yelped? can they not have yelped?
V-ing perfect
can I not have been yelping? can you not have been yelping? can she not have been yelping? can we not have been yelping? can you not have been yelping? can they not have been yelping?