GRAMMAR DETAIL

なり

as soon as

Indicates that the same person performed an unexpected second action immediately after completing the first.

Examples

彼は席に着くなり、報告書を開いた。

As soon as he sat down, he opened the report.

彼は電話を受けるなり、外へ出た。

As soon as he received the phone call, he went outside.

彼女は家に帰るなり、ベッドに横になった。

As soon as she got home, she lay down on the bed.

Structure: Attach なり to a dictionary-form verb to describe one person immediately following an action with another.
Basic usage: 彼は席に着くなり、報告書を開いた。 means that he opened the report as soon as he sat down.

Dictionary form even for a past action
- In 席に着くなり、開いた, sitting down also happened in the past, but the form is 着く. Do not replace this immediate-sequence connection with 着いたなり.
Subject compared with とたん
- 帰るなり横になった describes consecutive actions by the same person. とたん suits a separate event suddenly occurring afterward, as in 帰宅したとたん電話が鳴った.