Learn Hardcore Korean: gwiro eumageul deutgo nuneuro yeonghwareul bwayo. - I listen to music with my ears and watch a movie with my eyes.

In this sentence, 로 is the instrumental particle meaning “by means of” or “with.” When attached to a body part, it indicates you use that part to perform an action. So 귀로 듣다 means “listen with (your) ears,” and 눈으로 보다 means “see/watch with (your) eyes.”

Why is it 귀로 and 눈으로 instead of 귀에 and 눈에?

-에 marks location or target (“in/at the ear/eye”), while -로/으로 marks the means or instrument. Since you’re expressing “by using your ears/eyes,” you use -로, not -에.

What is the role of -고 between 듣고 and 봐요? Could you use 그리고 instead?

The suffix -고 directly connects verbs like “listening” and “watching” within one sentence, meaning “and.” It’s more concise than the conjunction 그리고, which tends to start a new clause or sentence. 듣고 … 봐요 is the natural way to say “listen and watch” in Korean.

Why are 음악 and 영화 marked with 을/를?

These particles mark the direct object of a verb. 음악을 듣다 means “to listen to music,” and 영화를 보다 means “to watch a movie.” Without 을/를, the sentence would lose the clear indication of what is being listened to or watched.

Why is the subject omitted in this sentence?

Korean often drops subjects when they’re clear from context. Here, the implied subject is “I” (제가/나는) or a general “you.” In everyday speech, Koreans omit pronouns if the listener can infer who’s doing the action.

Is the word order fixed? Could I say 음악을 귀로 듣고 영화를 눈으로 봐요 instead?

Yes—Korean word order is flexible because particles define each word’s function. 음악을 귀로 듣고 영화를 눈으로 봐요 is perfectly correct. The original order just places the body-part instrument first for emphasis or rhythm.

What formality level is 봐요?

봐요 is the polite informal present tense (often called the yo-form or 해요체). It’s appropriate for everyday conversations with people you’re not extremely close with but still want to be polite.

How would I say this in a more formal style?

You can use the formal polite -습니다 endings:
귀로 음악을 듣고 눈으로 영화를 봅니다.