can sweeten
Regular verb: sweeten - sweetened- sweetened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can sweeten
you can sweeten
she can sweeten
we can sweeten
you can sweeten
they can sweeten 	I can be sweetening
you can be sweetening
she can be sweetening
we can be sweetening
you can be sweetening
they can be sweetening	I can have sweetened
you can have sweetened
she can have sweetened
we can have sweetened
you can have sweetened
they can have sweetened	I can have been sweetening
you can have been sweetening
she can have been sweetening
we can have been sweetening
you can have been sweetening
they can have been sweetening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't sweeten
you can't sweeten
she can't sweeten
we can't sweeten
you can't sweeten
they can't sweeten 	I can't be sweetening
you can't be sweetening
she can't be sweetening
we can't be sweetening
you can't be sweetening
they can't be sweetening	I can't have sweetened
you can't have sweetened
she can't have sweetened
we can't have sweetened
you can't have sweetened
they can't have sweetened	I can't have been sweetening
you can't have been sweetening
she can't have been sweetening
we can't have been sweetening
you can't have been sweetening
they can't have been sweetening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I sweeten?
can you sweeten?
can she sweeten?
can we sweeten?
can you sweeten?
can they sweeten? 	can I be sweetening?
can you be sweetening?
can she be sweetening?
can we be sweetening?
can you be sweetening?
can they be sweetening? 	can I have sweetened?
can you have sweetened?
can she have sweetened?
can we have sweetened?
can you have sweetened?
can they have sweetened? 	can I have been sweetening?
can you have been sweetening?
can she have been sweetening?
can we have been sweetening?
can you have been sweetening?
can they have been sweetening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I sweeten?
can't you sweeten?
can't she sweeten?
can't we sweeten?
can't you sweeten?
can't they sweeten? 	can't I be sweetening?
can't you be sweetening?
can't she be sweetening?
can't we be sweetening?
can't you be sweetening?
can't they be sweetening? 	can't I have sweetened?
can't you have sweetened?
can't she have sweetened?
can't we have sweetened?
can't you have sweetened?
can't they have sweetened? 	can't I have been sweetening?
can't you have been sweetening?
can't she have been sweetening?
can't we have been sweetening?
can't you have been sweetening?
can't they have been sweetening?