could unriddle
Regular verb: unriddle - unriddled- unriddled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could unriddle
you could unriddle
he could unriddle
we could unriddle
you could unriddle
they could unriddle 	I could be unriddling
you could be unriddling
he could be unriddling
we could be unriddling
you could be unriddling
they could be unriddling	I could have unriddled
you could have unriddled
he could have unriddled
we could have unriddled
you could have unriddled
they could have unriddled	I could have been unriddling
you could have been unriddling
he could have been unriddling
we could have been unriddling
you could have been unriddling
they could have been unriddling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't unriddle
you couldn't unriddle
he couldn't unriddle
we couldn't unriddle
you couldn't unriddle
they couldn't unriddle 	I couldn't be unriddling
you couldn't be unriddling
he couldn't be unriddling
we couldn't be unriddling
you couldn't be unriddling
they couldn't be unriddling	I couldn't have unriddled
you couldn't have unriddled
he couldn't have unriddled
we couldn't have unriddled
you couldn't have unriddled
they couldn't have unriddled	I couldn't have been unriddling
you couldn't have been unriddling
he couldn't have been unriddling
we couldn't have been unriddling
you couldn't have been unriddling
they couldn't have been unriddling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I unriddle?
could you unriddle?
could he unriddle?
could we unriddle?
could you unriddle?
could they unriddle? 	could I be unriddling?
could you be unriddling?
could he be unriddling?
could we be unriddling?
could you be unriddling?
could they be unriddling? 	could I have unriddled?
could you have unriddled?
could he have unriddled?
could we have unriddled?
could you have unriddled?
could they have unriddled? 	could I have been unriddling?
could you have been unriddling?
could he have been unriddling?
could we have been unriddling?
could you have been unriddling?
could they have been unriddling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I unriddle?
couldn't you unriddle?
couldn't he unriddle?
couldn't we unriddle?
couldn't you unriddle?
couldn't they unriddle? 	couldn't I be unriddling?
couldn't you be unriddling?
couldn't he be unriddling?
couldn't we be unriddling?
couldn't you be unriddling?
couldn't they be unriddling? 	couldn't I have unriddled?
couldn't you have unriddled?
couldn't he have unriddled?
couldn't we have unriddled?
couldn't you have unriddled?
couldn't they have unriddled? 	couldn't I have been unriddling?
couldn't you have been unriddling?
couldn't he have been unriddling?
couldn't we have been unriddling?
couldn't you have been unriddling?
couldn't they have been unriddling?