I can yelp you can yelp he can yelp we can yelp you can yelp they can yelp
V-ing form
I can be yelping you can be yelping he can be yelping we can be yelping you can be yelping they can be yelping
Perfect
I can have yelped you can have yelped he 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 he can have been yelping we can have been yelping you can have been yelping they can have been yelping
Negation
Simple form
I can't yelp you can't yelp he can't yelp we can't yelp you can't yelp they can't yelp
V-ing form
I can't be yelping you can't be yelping he can't be yelping we can't be yelping you can't be yelping they can't be yelping
Perfect
I can't have yelped you can't have yelped he can't have yelped we can't have yelped you can't have yelped they can't have yelped
V-ing perfect
I can't have been yelping you can't have been yelping he can't have been yelping we can't have been yelping you can't have been yelping they can't have been yelping
Interrogative form
Simple form
can I yelp? can you yelp? can he yelp? can we yelp? can you yelp? can they yelp?
V-ing form
can I be yelping? can you be yelping? can he be yelping? can we be yelping? can you be yelping? can they be yelping?
Perfect
can I have yelped? can you have yelped? can he 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 he have been yelping? can we have been yelping? can you have been yelping? can they have been yelping?
Interro-negative form
Simple form
can't I yelp? can't you yelp? can't he yelp? can't we yelp? can't you yelp? can't they yelp?
V-ing form
can't I be yelping? can't you be yelping? can't he be yelping? can't we be yelping? can't you be yelping? can't they be yelping?
Perfect
can't I have yelped? can't you have yelped? can't he have yelped? can't we have yelped? can't you have yelped? can't they have yelped?
V-ing perfect
can't I have been yelping? can't you have been yelping? can't he have been yelping? can't we have been yelping? can't you have been yelping? can't they have been yelping?