Siri introduced the ability to translate phrases into foreign languages in an iOS 11 beta. But now it provides translations in 50 new languages, including English to Chinese, French, German, Italian and Spanish.
You can tell Siri to translate a phrase in several ways. For example:
“Translate to [Language]”
“How do I say [phrase] in [Language]?”
Siri shows the translated phrase on screen and pronounces it, as well.