I could prevent you could prevent she could prevent we could prevent you could prevent they could prevent
Forma con V-ing
I could be preventing you could be preventing she could be preventing we could be preventing you could be preventing they could be preventing
Perfecto
I could have prevented you could have prevented she could have prevented we could have prevented you could have prevented they could have prevented
Perfecto con V-ing
I could have been preventing you could have been preventing she could have been preventing we could have been preventing you could have been preventing they could have been preventing
Negación
Forma simple
I couldn't prevent you couldn't prevent she couldn't prevent we couldn't prevent you couldn't prevent they couldn't prevent
Forma con V-ing
I couldn't be preventing you couldn't be preventing she couldn't be preventing we couldn't be preventing you couldn't be preventing they couldn't be preventing
Perfecto
I couldn't have prevented you couldn't have prevented she couldn't have prevented we couldn't have prevented you couldn't have prevented they couldn't have prevented
Perfecto con V-ing
I couldn't have been preventing you couldn't have been preventing she couldn't have been preventing we couldn't have been preventing you couldn't have been preventing they couldn't have been preventing
Forma interrogativa
Forma simple
could I prevent? could you prevent? could she prevent? could we prevent? could you prevent? could they prevent?
Forma con V-ing
could I be preventing? could you be preventing? could she be preventing? could we be preventing? could you be preventing? could they be preventing?
Perfecto
could I have prevented? could you have prevented? could she have prevented? could we have prevented? could you have prevented? could they have prevented?
Perfecto con V-ing
could I have been preventing? could you have been preventing? could she have been preventing? could we have been preventing? could you have been preventing? could they have been preventing?
Forma interro-negativa
Forma simple
couldn't I prevent? couldn't you prevent? couldn't she prevent? couldn't we prevent? couldn't you prevent? couldn't they prevent?
Forma con V-ing
couldn't I be preventing? couldn't you be preventing? couldn't she be preventing? couldn't we be preventing? couldn't you be preventing? couldn't they be preventing?
Perfecto
couldn't I have prevented? couldn't you have prevented? couldn't she have prevented? couldn't we have prevented? couldn't you have prevented? couldn't they have prevented?
Perfecto con V-ing
couldn't I have been preventing? couldn't you have been preventing? couldn't she have been preventing? couldn't we have been preventing? couldn't you have been preventing? couldn't they have been preventing?