にいる時

when in

→ に
phrase Rare #37,187
when in Used to say “when someone is in or at a place.” The person can be stated before に or understood from context.
JA: 日本にいる時は、毎朝早く起きていました。
EN: When I was in Japan, I used to get up early every morning.

イギリスにいる時英語を話すのにとても苦労した

When I was in England, I had a very hard time speaking English.

トイレにいる時ドアを閉めなさい

Close the door when you’re in the bathroom.

その詩人に初めて会ったのは私が北海道にいる時だった

I first met that poet when I was in Hokkaido.

大草原にいる時のようなのざわめきが聞こえてくる

I can hear the rustling of leaves, as if I were out on the great plains.

— レオン (1994)