can whistle
Regular verb: whistle - whistled- whistled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can whistle
you can whistle
she can whistle
we can whistle
you can whistle
they can whistle 	I can be whistling
you can be whistling
she can be whistling
we can be whistling
you can be whistling
they can be whistling	I can have whistled
you can have whistled
she can have whistled
we can have whistled
you can have whistled
they can have whistled	I can have been whistling
you can have been whistling
she can have been whistling
we can have been whistling
you can have been whistling
they can have been whistling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot whistle
you cannot whistle
she cannot whistle
we cannot whistle
you cannot whistle
they cannot whistle 	I cannot be whistling
you cannot be whistling
she cannot be whistling
we cannot be whistling
you cannot be whistling
they cannot be whistling	I cannot have whistled
you cannot have whistled
she cannot have whistled
we cannot have whistled
you cannot have whistled
they cannot have whistled	I cannot have been whistling
you cannot have been whistling
she cannot have been whistling
we cannot have been whistling
you cannot have been whistling
they cannot have been whistling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I whistle?
can you whistle?
can she whistle?
can we whistle?
can you whistle?
can they whistle? 	can I be whistling?
can you be whistling?
can she be whistling?
can we be whistling?
can you be whistling?
can they be whistling? 	can I have whistled?
can you have whistled?
can she have whistled?
can we have whistled?
can you have whistled?
can they have whistled? 	can I have been whistling?
can you have been whistling?
can she have been whistling?
can we have been whistling?
can you have been whistling?
can they have been whistling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not whistle?
can you not whistle?
can she not whistle?
can we not whistle?
can you not whistle?
can they not whistle? 	can I not be whistling?
can you not be whistling?
can she not be whistling?
can we not be whistling?
can you not be whistling?
can they not be whistling? 	can I not have whistled?
can you not have whistled?
can she not have whistled?
can we not have whistled?
can you not have whistled?
can they not have whistled? 	can I not have been whistling?
can you not have been whistling?
can she not have been whistling?
can we not have been whistling?
can you not have been whistling?
can they not have been whistling?