Add `RNI18n.xcodeproj` to **Libraries** and add `libRNI18n.a` to **Link Binary With Libraries** under **Build Phases**. [More info and screenshots about how to do this is available in the React Native documentation](http://facebook.github.io/react-native/docs/linking-libraries.html).
When fallbacks are enabled (which is generally recommended), `i18n.js` will try to look up translations in the following order (for a device with `en_US` locale):
- en-US
- en
**Note**: iOS locales use underscored (`en_US`) but `i18n.js` locales are dasherized (`en-US`). This conversion is done automatically for you.
```js
I18n.fallbacks = true;
I18n.translations = {
'en': {
greeting: 'Hi!'
},
'en-GB': {
greeting: 'Hi from the UK!'
}
}
```
For a device with a `en_GB` locale this will return `Hi from the UK!'`, for a device with a `en_US` locale it will return `Hi!`.