can richen
Regular verb: richen - richened- richened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can richen
you can richen
she can richen
we can richen
you can richen
they can richen 	I can be richening
you can be richening
she can be richening
we can be richening
you can be richening
they can be richening	I can have richened
you can have richened
she can have richened
we can have richened
you can have richened
they can have richened	I can have been richening
you can have been richening
she can have been richening
we can have been richening
you can have been richening
they can have been richening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot richen
you cannot richen
she cannot richen
we cannot richen
you cannot richen
they cannot richen 	I cannot be richening
you cannot be richening
she cannot be richening
we cannot be richening
you cannot be richening
they cannot be richening	I cannot have richened
you cannot have richened
she cannot have richened
we cannot have richened
you cannot have richened
they cannot have richened	I cannot have been richening
you cannot have been richening
she cannot have been richening
we cannot have been richening
you cannot have been richening
they cannot have been richening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I richen?
can you richen?
can she richen?
can we richen?
can you richen?
can they richen? 	can I be richening?
can you be richening?
can she be richening?
can we be richening?
can you be richening?
can they be richening? 	can I have richened?
can you have richened?
can she have richened?
can we have richened?
can you have richened?
can they have richened? 	can I have been richening?
can you have been richening?
can she have been richening?
can we have been richening?
can you have been richening?
can they have been richening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not richen?
can you not richen?
can she not richen?
can we not richen?
can you not richen?
can they not richen? 	can I not be richening?
can you not be richening?
can she not be richening?
can we not be richening?
can you not be richening?
can they not be richening? 	can I not have richened?
can you not have richened?
can she not have richened?
can we not have richened?
can you not have richened?
can they not have richened? 	can I not have been richening?
can you not have been richening?
can she not have been richening?
can we not have been richening?
can you not have been richening?
can they not have been richening?