could tango
Regular verb: tango - tangoed- tangoed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could tango
you could tango
she could tango
we could tango
you could tango
they could tango 	I could be tangoing
you could be tangoing
she could be tangoing
we could be tangoing
you could be tangoing
they could be tangoing	I could have tangoed
you could have tangoed
she could have tangoed
we could have tangoed
you could have tangoed
they could have tangoed	I could have been tangoing
you could have been tangoing
she could have been tangoing
we could have been tangoing
you could have been tangoing
they could have been tangoing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't tango
you couldn't tango
she couldn't tango
we couldn't tango
you couldn't tango
they couldn't tango 	I couldn't be tangoing
you couldn't be tangoing
she couldn't be tangoing
we couldn't be tangoing
you couldn't be tangoing
they couldn't be tangoing	I couldn't have tangoed
you couldn't have tangoed
she couldn't have tangoed
we couldn't have tangoed
you couldn't have tangoed
they couldn't have tangoed	I couldn't have been tangoing
you couldn't have been tangoing
she couldn't have been tangoing
we couldn't have been tangoing
you couldn't have been tangoing
they couldn't have been tangoing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I tango?
could you tango?
could she tango?
could we tango?
could you tango?
could they tango? 	could I be tangoing?
could you be tangoing?
could she be tangoing?
could we be tangoing?
could you be tangoing?
could they be tangoing? 	could I have tangoed?
could you have tangoed?
could she have tangoed?
could we have tangoed?
could you have tangoed?
could they have tangoed? 	could I have been tangoing?
could you have been tangoing?
could she have been tangoing?
could we have been tangoing?
could you have been tangoing?
could they have been tangoing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I tango?
couldn't you tango?
couldn't she tango?
couldn't we tango?
couldn't you tango?
couldn't they tango? 	couldn't I be tangoing?
couldn't you be tangoing?
couldn't she be tangoing?
couldn't we be tangoing?
couldn't you be tangoing?
couldn't they be tangoing? 	couldn't I have tangoed?
couldn't you have tangoed?
couldn't she have tangoed?
couldn't we have tangoed?
couldn't you have tangoed?
couldn't they have tangoed? 	couldn't I have been tangoing?
couldn't you have been tangoing?
couldn't she have been tangoing?
couldn't we have been tangoing?
couldn't you have been tangoing?
couldn't they have been tangoing?