“해라체 itself is one of the endings. It’s the ‘-라’ ending of 해라체 combined with various verbs. Sleep(자다 + -라), Write it(쓰다 + -라), Read it(읽다 + -으라), etc. There are various endings like 해라체, depending on the level of respect towards the listener(person on the other end of the conversation). Such as 반말체, 하게체, 해요체, and 하십시오체. They are endings that put the listener in a higher up position as you go on (meaning 하십시오체 is more formal than 해요체, etc)!”