
Verbo regular: prevent - prevented - prevented
Forma simple | Forma con V-ing | 
| I could prevent you could prevent he could prevent we could prevent you could prevent they could prevent  | I could be preventing you could be preventing he could be preventing we could be preventing you could be preventing they could be preventing  | 
Perfecto | Perfecto con V-ing | 
| I could have prevented you could have prevented he could have prevented we could have prevented you could have prevented they could have prevented  | I could have been preventing you could have been preventing he could have been preventing we could have been preventing you could have been preventing they could have been preventing  | 
Forma simple | Forma con V-ing | 
| I couldn't prevent you couldn't prevent he couldn't prevent we couldn't prevent you couldn't prevent they couldn't prevent  | I couldn't be preventing you couldn't be preventing he couldn't be preventing we couldn't be preventing you couldn't be preventing they couldn't be preventing  | 
Perfecto | Perfecto con V-ing | 
| I couldn't have prevented you couldn't have prevented he couldn't have prevented we couldn't have prevented you couldn't have prevented they couldn't have prevented  | I couldn't have been preventing you couldn't have been preventing he couldn't have been preventing we couldn't have been preventing you couldn't have been preventing they couldn't have been preventing  | 
Forma simple | Forma con V-ing | 
| could I prevent? could you prevent? could he prevent? could we prevent? could you prevent? could they prevent?  | could I be preventing? could you be preventing? could he be preventing? could we be preventing? could you be preventing? could they be preventing?  | 
Perfecto | Perfecto con V-ing | 
| could I have prevented? could you have prevented? could he have prevented? could we have prevented? could you have prevented? could they have prevented?  | could I have been preventing? could you have been preventing? could he have been preventing? could we have been preventing? could you have been preventing? could they have been preventing?  | 
Forma simple | Forma con V-ing | 
| couldn't I prevent? couldn't you prevent? couldn't he prevent? couldn't we prevent? couldn't you prevent? couldn't they prevent?  | couldn't I be preventing? couldn't you be preventing? couldn't he be preventing? couldn't we be preventing? couldn't you be preventing? couldn't they be preventing?  | 
Perfecto | Perfecto con V-ing | 
| couldn't I have prevented? couldn't you have prevented? couldn't he have prevented? couldn't we have prevented? couldn't you have prevented? couldn't they have prevented?  | couldn't I have been preventing? couldn't you have been preventing? couldn't he have been preventing? couldn't we have been preventing? couldn't you have been preventing? couldn't they have been preventing?  |