I could tub you could tub she could tub we could tub you could tub they could tub
Forma con V-ing
I could be tubbing you could be tubbing she could be tubbing we could be tubbing you could be tubbing they could be tubbing
Perfecto
I could have tubbed you could have tubbed she could have tubbed we could have tubbed you could have tubbed they could have tubbed
Perfecto con V-ing
I could have been tubbing you could have been tubbing she could have been tubbing we could have been tubbing you could have been tubbing they could have been tubbing
Negación
Forma simple
I could not tub you could not tub she could not tub we could not tub you could not tub they could not tub
Forma con V-ing
I could not be tubbing you could not be tubbing she could not be tubbing we could not be tubbing you could not be tubbing they could not be tubbing
Perfecto
I could not have tubbed you could not have tubbed she could not have tubbed we could not have tubbed you could not have tubbed they could not have tubbed
Perfecto con V-ing
I could not have been tubbing you could not have been tubbing she could not have been tubbing we could not have been tubbing you could not have been tubbing they could not have been tubbing
Forma interrogativa
Forma simple
could I tub? could you tub? could she tub? could we tub? could you tub? could they tub?
Forma con V-ing
could I be tubbing? could you be tubbing? could she be tubbing? could we be tubbing? could you be tubbing? could they be tubbing?
Perfecto
could I have tubbed? could you have tubbed? could she have tubbed? could we have tubbed? could you have tubbed? could they have tubbed?
Perfecto con V-ing
could I have been tubbing? could you have been tubbing? could she have been tubbing? could we have been tubbing? could you have been tubbing? could they have been tubbing?
Forma interro-negativa
Forma simple
could I not tub? could you not tub? could she not tub? could we not tub? could you not tub? could they not tub?
Forma con V-ing
could I not be tubbing? could you not be tubbing? could she not be tubbing? could we not be tubbing? could you not be tubbing? could they not be tubbing?
Perfecto
could I not have tubbed? could you not have tubbed? could she not have tubbed? could we not have tubbed? could you not have tubbed? could they not have tubbed?
Perfecto con V-ing
could I not have been tubbing? could you not have been tubbing? could she not have been tubbing? could we not have been tubbing? could you not have been tubbing? could they not have been tubbing?