One Friday afternoon at a public elementary school in central Tokyo, a Japanese-language teacher was explaining how to say the time of day to a Ukrainian girl who came to Japan after she and her family fled her country following Russia's invasion.

When the teacher asked what time she woke up that morning, Olivia Zhuravel, 13, wrote down the answer — that she woke up at 6:45 a.m. — in hiragana.

“You see that it always comes with a ni after the time?” said Isuzu Yagi, the teacher. Olivia, a sixth grader, nodded but then tilted her head as if she was not entirely sure.