Trasformazione da forma passiva a forma attiva
Le frasi alla forma attiva sono più semplici da comprendere delle frasi formulate alla forma passiva. Trasformare una forma passiva in una forma attiva è semplice, ma richiede un po' di pratica. Nella tabella di equivalenza riportata qui di seguito si nota che il tempo dell'ausiliare to be nella forma passiva è sempre uguale al tempo del verbo principale della forma attiva. Per trasformare la frase in attiva, il soggetto della frase deve diventare esplicito
Forme attiva e passiva di 'to keep'
| Forma | Attiva | Passiva | Frase attiva | Frase passiva |
|---|---|---|---|---|
| Simple present | keep | is kept | I keep the butter in the fridge. | The butter is kept in the fridge. |
| Present continuous | is keeping | is being kept | John is keeping my house tidy. | My house is being kept tidy. |
| Simple past | kept | was kept | Mary kept her schedule meticulously. | Mary's schedule was kept meticulously. |
| Past continuous | was keeping | was being kept | The theater was keeping a seat for you. | A seat was being kept for you. |
| Present perfect | have kept | have been kept | I have kept all your old letters. | All your old letters have been kept. |
| Past perfect | had kept | had been kept | He had kept up his training regimen for a month. | His training regimen had been kept up for a month. |
| Simple future | will keep | will be kept | Mark will keep the ficus. | The ficus will be kept. |
| Condizionale presente | would keep | would be kept | If you told me, I would keep your secret. | If you told me, your secret would be kept. |
| Condizionale passato | would have kept | would have been kept | I would have kept your bicycle here if you had left it with me. | Your bicycle would have been kept here if you had left it with me. |
| Infinito presente | to keep | to be kept | She wants to keep the book. | The book wants to be kept. |
| Infinito passato | to have kept | to have been kept | Judy was happy to have kept the puppy. | The puppy was happy to have been kept. |
| Participio presente e gerundio | keeping | being kept | I have a feeling that you may be keeping a secret. | I have a feeling that a secret may be being kept. |
| Gerundio passato | having kept | having been kept | Having kept the bird in a cage for so long, Jade wasn't sure it could survive in the wild. | The bird, having been kept in a cage for so long, might not survive in the wild. |