How do I install hyphenation package?

How do I install hyphenation package for locale “en”.

“en” by itself doesn’t exist in LibreOffice. Google Docs might have mangled the language of your document a bit. You could try selecting all the text and converting it to English (USA), English (UK) or the English of your locale and see if that fixes the issue. Tools > Language > For All Text > English (your locale)