It is illegal to read people's private letters without permission.

私自阅读别人的信件是违法的。

youdao

I was very angry with my mother because I caught her reading my private letters.

我对我妈妈感到很生气，因为我发现她在偷看我的私人信件。

youdao

Parents should realize that it's illegal to read their children's private letters without permission.

父母应该意识到，未经许可读孩子的私人信件是违法的。

youdao

The author had conflicting thoughts on whether he wanted the public to read his private letters.

BBC: TS Eliot

In her private letters to the four parties, she urges action from the leaders.

BBC: Rosemary Butler

Virtually no royal accounts survive for 1415, and almost no private letters.

ECONOMIST: Henry V, English hero