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 couldn't tenon
you couldn't tenon
she couldn't tenon
we couldn't tenon
you couldn't tenon
they couldn't tenon 	I couldn't be tenoning
you couldn't be tenoning
she couldn't be tenoning
we couldn't be tenoning
you couldn't be tenoning
they couldn't be tenoning	I couldn't have tenoned
you couldn't have tenoned
she couldn't have tenoned
we couldn't have tenoned
you couldn't have tenoned
they couldn't have tenoned	I couldn't have been tenoning
you couldn't have been tenoning
she couldn't have been tenoning
we couldn't have been tenoning
you couldn't have been tenoning
they couldn't 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 	
couldn't I tenon?
couldn't you tenon?
couldn't she tenon?
couldn't we tenon?
couldn't you tenon?
couldn't they tenon? 	couldn't I be tenoning?
couldn't you be tenoning?
couldn't she be tenoning?
couldn't we be tenoning?
couldn't you be tenoning?
couldn't they be tenoning? 	couldn't I have tenoned?
couldn't you have tenoned?
couldn't she have tenoned?
couldn't we have tenoned?
couldn't you have tenoned?
couldn't they have tenoned? 	couldn't I have been tenoning?
couldn't you have been tenoning?
couldn't she have been tenoning?
couldn't we have been tenoning?
couldn't you have been tenoning?
couldn't they have been tenoning?