| Subject | Russian | English |
| Игорь Миг | доподлинно известно | know full well |
| gen. | доподлинно известно | know for a fact (требует замены конструкции с личной на безличную Beloshapkina) |
| gen. | доподлинно известно | it is known for a fact (It is known for a fact, because it is something that already took place. • It is known for a fact that the Chinese made rockets and fireworks long before gunpowder was used in Europe. 4uzhoj) |
| gen. | доподлинно известно | it is known for certain (Anglophile) |
| gen. | Доподлинно неизвестно | it is not certain (Skillchik) |
| obs. | мне доподлинно известно | to my certain knowledge (Abysslooker) |
| Игорь Миг | мне доподлинно известно | I know for a fact |
| inf. | мне это доподлинно известно | I know it for certain |
| gen. | очень часто не удаётся доподлинно установить причину смерти клонов | clones have been known to die mysteriously (bigmaxus) |
| rhetor. | это доподлинно неизвестно | we don't know with absolute certainty (CNN, 2020 Alex_Odeychuk) |