At a glance
～てはじめて means "only after doing X" or "not until X". It shows that something happened, or was understood, for the first time only after a certain experience.
Verb て-form + はじめて、[new event / realization]
病気になってはじめて、健康の大切さがわかりました。 It was only after I got sick that I understood the importance of health.
How to form it
Put the verb in the て-form and add はじめて. The grammar itself is neutral; politeness comes from the verb at the end of the sentence.
| Verb group | Dictionary form | て-form + はじめて |
|---|---|---|
| う-verb | 会う | 会ってはじめて |
| う-verb | 住む | 住んではじめて |
| う-verb (exception) | 行く | 行ってはじめて |
| る-verb | 見る | 見てはじめて |
| する | する | してはじめて |
| 来る | 来る | 来てはじめて |
With nouns, use になって: 大人になってはじめて "only after becoming an adult".