can smoothen
Regular verb: smoothen - smoothened- smoothened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can smoothen
you can smoothen
he can smoothen
we can smoothen
you can smoothen
they can smoothen 	I can be smoothening
you can be smoothening
he can be smoothening
we can be smoothening
you can be smoothening
they can be smoothening	I can have smoothened
you can have smoothened
he can have smoothened
we can have smoothened
you can have smoothened
they can have smoothened	I can have been smoothening
you can have been smoothening
he can have been smoothening
we can have been smoothening
you can have been smoothening
they can have been smoothening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't smoothen
you can't smoothen
he can't smoothen
we can't smoothen
you can't smoothen
they can't smoothen 	I can't be smoothening
you can't be smoothening
he can't be smoothening
we can't be smoothening
you can't be smoothening
they can't be smoothening	I can't have smoothened
you can't have smoothened
he can't have smoothened
we can't have smoothened
you can't have smoothened
they can't have smoothened	I can't have been smoothening
you can't have been smoothening
he can't have been smoothening
we can't have been smoothening
you can't have been smoothening
they can't have been smoothening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I smoothen?
can you smoothen?
can he smoothen?
can we smoothen?
can you smoothen?
can they smoothen? 	can I be smoothening?
can you be smoothening?
can he be smoothening?
can we be smoothening?
can you be smoothening?
can they be smoothening? 	can I have smoothened?
can you have smoothened?
can he have smoothened?
can we have smoothened?
can you have smoothened?
can they have smoothened? 	can I have been smoothening?
can you have been smoothening?
can he have been smoothening?
can we have been smoothening?
can you have been smoothening?
can they have been smoothening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I smoothen?
can't you smoothen?
can't he smoothen?
can't we smoothen?
can't you smoothen?
can't they smoothen? 	can't I be smoothening?
can't you be smoothening?
can't he be smoothening?
can't we be smoothening?
can't you be smoothening?
can't they be smoothening? 	can't I have smoothened?
can't you have smoothened?
can't he have smoothened?
can't we have smoothened?
can't you have smoothened?
can't they have smoothened? 	can't I have been smoothening?
can't you have been smoothening?
can't he have been smoothening?
can't we have been smoothening?
can't you have been smoothening?
can't they have been smoothening?