| He might have written it last week. | | |
| He must have failed to prepare the translation beforehand. | | |
| It must have been someone of his colleagues. | | |
| She was to have come half an hour ago. | | |
| It is to be thought of as a sort of a radioactivity. | | |
| Nay, if it is to be guesswork, let us all guess for ourselves. | | |
| The programme is to be carried out during water intake during the operational period. | | |