I could frog you could frog he could frog we could frog you could frog they could frog
Forme en V-ing
I could be froging you could be froging he could be froging we could be froging you could be froging they could be froging
Perfect
I could have froged you could have froged he could have froged we could have froged you could have froged they could have froged
Perfect en V-ing
I could have been froging you could have been froging he could have been froging we could have been froging you could have been froging they could have been froging
Négation
Forme simple
I could not frog you could not frog he could not frog we could not frog you could not frog they could not frog
Forme en V-ing
I could not be froging you could not be froging he could not be froging we could not be froging you could not be froging they could not be froging
Perfect
I could not have froged you could not have froged he could not have froged we could not have froged you could not have froged they could not have froged
Perfect en V-ing
I could not have been froging you could not have been froging he could not have been froging we could not have been froging you could not have been froging they could not have been froging
Forme interrogative
Forme simple
could I frog? could you frog? could he frog? could we frog? could you frog? could they frog?
Forme en V-ing
could I be froging? could you be froging? could he be froging? could we be froging? could you be froging? could they be froging?
Perfect
could I have froged? could you have froged? could he have froged? could we have froged? could you have froged? could they have froged?
Perfect en V-ing
could I have been froging? could you have been froging? could he have been froging? could we have been froging? could you have been froging? could they have been froging?
Forme interro-négative
Forme simple
could I not frog? could you not frog? could he not frog? could we not frog? could you not frog? could they not frog?
Forme en V-ing
could I not be froging? could you not be froging? could he not be froging? could we not be froging? could you not be froging? could they not be froging?
Perfect
could I not have froged? could you not have froged? could he not have froged? could we not have froged? could you not have froged? could they not have froged?
Perfect en V-ing
could I not have been froging? could you not have been froging? could he not have been froging? could we not have been froging? could you not have been froging? could they not have been froging?