English verb conjugation
COULD TENON

Regular verb: tenon - tenoned - tenoned

Affirmation

Simple form	V-ing form
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
Perfect	V-ing perfect
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
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
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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?