I could letch you could letch he could letch we could letch you could letch they could letch
Forme en V-ing
I could be letching you could be letching he could be letching we could be letching you could be letching they could be letching
Perfect
I could have letched you could have letched he could have letched we could have letched you could have letched they could have letched
Perfect en V-ing
I could have been letching you could have been letching he could have been letching we could have been letching you could have been letching they could have been letching
Négation
Forme simple
I could not letch you could not letch he could not letch we could not letch you could not letch they could not letch
Forme en V-ing
I could not be letching you could not be letching he could not be letching we could not be letching you could not be letching they could not be letching
Perfect
I could not have letched you could not have letched he could not have letched we could not have letched you could not have letched they could not have letched
Perfect en V-ing
I could not have been letching you could not have been letching he could not have been letching we could not have been letching you could not have been letching they could not have been letching
Forme interrogative
Forme simple
could I letch? could you letch? could he letch? could we letch? could you letch? could they letch?
Forme en V-ing
could I be letching? could you be letching? could he be letching? could we be letching? could you be letching? could they be letching?
Perfect
could I have letched? could you have letched? could he have letched? could we have letched? could you have letched? could they have letched?
Perfect en V-ing
could I have been letching? could you have been letching? could he have been letching? could we have been letching? could you have been letching? could they have been letching?
Forme interro-négative
Forme simple
could I not letch? could you not letch? could he not letch? could we not letch? could you not letch? could they not letch?
Forme en V-ing
could I not be letching? could you not be letching? could he not be letching? could we not be letching? could you not be letching? could they not be letching?
Perfect
could I not have letched? could you not have letched? could he not have letched? could we not have letched? could you not have letched? could they not have letched?
Perfect en V-ing
could I not have been letching? could you not have been letching? could he not have been letching? could we not have been letching? could you not have been letching? could they not have been letching?