can tumble
Regular verb: tumble - tumbled- tumbled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can tumble
you can tumble
he can tumble
we can tumble
you can tumble
they can tumble 	I can be tumbling
you can be tumbling
he can be tumbling
we can be tumbling
you can be tumbling
they can be tumbling	I can have tumbled
you can have tumbled
he can have tumbled
we can have tumbled
you can have tumbled
they can have tumbled	I can have been tumbling
you can have been tumbling
he can have been tumbling
we can have been tumbling
you can have been tumbling
they can have been tumbling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't tumble
you can't tumble
he can't tumble
we can't tumble
you can't tumble
they can't tumble 	I can't be tumbling
you can't be tumbling
he can't be tumbling
we can't be tumbling
you can't be tumbling
they can't be tumbling	I can't have tumbled
you can't have tumbled
he can't have tumbled
we can't have tumbled
you can't have tumbled
they can't have tumbled	I can't have been tumbling
you can't have been tumbling
he can't have been tumbling
we can't have been tumbling
you can't have been tumbling
they can't have been tumbling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I tumble?
can you tumble?
can he tumble?
can we tumble?
can you tumble?
can they tumble? 	can I be tumbling?
can you be tumbling?
can he be tumbling?
can we be tumbling?
can you be tumbling?
can they be tumbling? 	can I have tumbled?
can you have tumbled?
can he have tumbled?
can we have tumbled?
can you have tumbled?
can they have tumbled? 	can I have been tumbling?
can you have been tumbling?
can he have been tumbling?
can we have been tumbling?
can you have been tumbling?
can they have been tumbling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I tumble?
can't you tumble?
can't he tumble?
can't we tumble?
can't you tumble?
can't they tumble? 	can't I be tumbling?
can't you be tumbling?
can't he be tumbling?
can't we be tumbling?
can't you be tumbling?
can't they be tumbling? 	can't I have tumbled?
can't you have tumbled?
can't he have tumbled?
can't we have tumbled?
can't you have tumbled?
can't they have tumbled? 	can't I have been tumbling?
can't you have been tumbling?
can't he have been tumbling?
can't we have been tumbling?
can't you have been tumbling?
can't they have been tumbling?