When you write in Hangul do you write the English or Roman?

When writing in Hangul, the Korean script, one typically does not use English or Roman letters, as Hangul is specifically designed for the Korean language. However, in contexts where romanization is necessary, such as for non-Korean speakers, the Roman alphabet can be used to transliterate Korean Words. This practice is common in language learning or in informal settings, but it is separate from writing in Hangul itself.