English Translation
How’s work?
The root of 어때 (eottae) is the word 어떻다 (eotteohda), which means “how” or “what.”
The -ㄹ/-을 (-l/eul) ending is added to the stem 어떻 (eotteok) to make the phrase 어떻다 (eotteohda) into the adjective “how,” and the verb ending -아/-어 (-a/eo) is added to make it into the question form, 어떻다 + -아/-어 = 어떻어 (eotteoh-eo).
This is then contracted to 어때 (eottae) for easier pronunciation.