Change Text-to-speech language

Make sure the voice pack of the language is installed in the phone before you change the TTS language.

By default the TTS's language is determined by the phone's language. If the language of the phone is English then the TTS language will also be the same.

You can change this by going into the PostFragment.java

if (i == TextToSpeech.SUCCESS) {
    int result = tts.setLanguage(Locale.getDefault());

    if (result == TextToSpeech.LANG_MISSING_DATA
            || result == TextToSpeech.LANG_NOT_SUPPORTED) {
        showSnackbar(getResources().getString(R.string.text_to_speak_language_not_supported));
    }
} else {
    Log.e("TTS", "Initilization Failed!");
}

Change the Locale.getDefault() with new Locale("fr","CA"). fr is the language and CA is the country. Check the list of available locale https://www.oracle.com/technetwork/java/javase/java8locales-2095355.html

if (i == TextToSpeech.SUCCESS) {
    int result = tts.setLanguage(new Locale("fr","CA"));

    if (result == TextToSpeech.LANG_MISSING_DATA
            || result == TextToSpeech.LANG_NOT_SUPPORTED) {
        showSnackbar(getResources().getString(R.string.text_to_speak_language_not_supported));
    }
} else {
    Log.e("TTS", "Initilization Failed!");
}