can bubble
Regular verb: bubble - bubbled- bubbled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can bubble
you can bubble
he can bubble
we can bubble
you can bubble
they can bubble 	I can be bubbling
you can be bubbling
he can be bubbling
we can be bubbling
you can be bubbling
they can be bubbling	I can have bubbled
you can have bubbled
he can have bubbled
we can have bubbled
you can have bubbled
they can have bubbled	I can have been bubbling
you can have been bubbling
he can have been bubbling
we can have been bubbling
you can have been bubbling
they can have been bubbling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't bubble
you can't bubble
he can't bubble
we can't bubble
you can't bubble
they can't bubble 	I can't be bubbling
you can't be bubbling
he can't be bubbling
we can't be bubbling
you can't be bubbling
they can't be bubbling	I can't have bubbled
you can't have bubbled
he can't have bubbled
we can't have bubbled
you can't have bubbled
they can't have bubbled	I can't have been bubbling
you can't have been bubbling
he can't have been bubbling
we can't have been bubbling
you can't have been bubbling
they can't have been bubbling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I bubble?
can you bubble?
can he bubble?
can we bubble?
can you bubble?
can they bubble? 	can I be bubbling?
can you be bubbling?
can he be bubbling?
can we be bubbling?
can you be bubbling?
can they be bubbling? 	can I have bubbled?
can you have bubbled?
can he have bubbled?
can we have bubbled?
can you have bubbled?
can they have bubbled? 	can I have been bubbling?
can you have been bubbling?
can he have been bubbling?
can we have been bubbling?
can you have been bubbling?
can they have been bubbling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I bubble?
can't you bubble?
can't he bubble?
can't we bubble?
can't you bubble?
can't they bubble? 	can't I be bubbling?
can't you be bubbling?
can't he be bubbling?
can't we be bubbling?
can't you be bubbling?
can't they be bubbling? 	can't I have bubbled?
can't you have bubbled?
can't he have bubbled?
can't we have bubbled?
can't you have bubbled?
can't they have bubbled? 	can't I have been bubbling?
can't you have been bubbling?
can't he have been bubbling?
can't we have been bubbling?
can't you have been bubbling?
can't they have been bubbling?