could tenon
Regular verb: tenon - tenoned- tenoned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could tenon
you could tenon
she could tenon
we could tenon
you could tenon
they could tenon 	I could be tenoning
you could be tenoning
she could be tenoning
we could be tenoning
you could be tenoning
they could be tenoning	I could have tenoned
you could have tenoned
she could have tenoned
we could have tenoned
you could have tenoned
they could have tenoned	I could have been tenoning
you could have been tenoning
she could have been tenoning
we could have been tenoning
you could have been tenoning
they could have been tenoning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not tenon
you could not tenon
she could not tenon
we could not tenon
you could not tenon
they could not tenon 	I could not be tenoning
you could not be tenoning
she could not be tenoning
we could not be tenoning
you could not be tenoning
they could not be tenoning	I could not have tenoned
you could not have tenoned
she could not have tenoned
we could not have tenoned
you could not have tenoned
they could not have tenoned	I could not have been tenoning
you could not have been tenoning
she could not have been tenoning
we could not have been tenoning
you could not have been tenoning
they could not have been tenoning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I tenon?
could you tenon?
could she tenon?
could we tenon?
could you tenon?
could they tenon? 	could I be tenoning?
could you be tenoning?
could she be tenoning?
could we be tenoning?
could you be tenoning?
could they be tenoning? 	could I have tenoned?
could you have tenoned?
could she have tenoned?
could we have tenoned?
could you have tenoned?
could they have tenoned? 	could I have been tenoning?
could you have been tenoning?
could she have been tenoning?
could we have been tenoning?
could you have been tenoning?
could they have been tenoning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not tenon?
could you not tenon?
could she not tenon?
could we not tenon?
could you not tenon?
could they not tenon? 	could I not be tenoning?
could you not be tenoning?
could she not be tenoning?
could we not be tenoning?
could you not be tenoning?
could they not be tenoning? 	could I not have tenoned?
could you not have tenoned?
could she not have tenoned?
could we not have tenoned?
could you not have tenoned?
could they not have tenoned? 	could I not have been tenoning?
could you not have been tenoning?
could she not have been tenoning?
could we not have been tenoning?
could you not have been tenoning?
could they not have been tenoning?