Learn Hardcore Korean: jidoreul bogo ttokbaro georeoyo. - I look at the map and walk straight.

보고 here is the connective form of the verb 보다 (“to look”) plus -고, which links two actions. In other words, 지도를 보고 means “look at the map and …,” implying “after (or while) looking at the map.” So the sentence literally says, “Look at the map, then walk straight.”

Why is the verb 걷다 conjugated as 걸어요 instead of 걷어요?

걷다 is a ㄷ-irregular verb. When the stem ends in ㄷ and a vowel-initial ending (like -어요) follows, the ㄷ changes to ㄹ. Hence:
• 걷 + 어요 → 걸어요

What does 똑바로 mean, and what exactly does it modify?

똑바로 is an adverb meaning “straight” (in direction) or “properly.” Here it modifies 걸어요, telling you how to walk. In context, it most naturally means “go straight” rather than “walk properly.”

Could 똑바로 걸어요 ever mean “walk properly” instead of “walk straight”?

Yes, 똑바로 걸어요 can mean “walk with good posture” or “walk properly,” especially if the context is about etiquette or posture. But when giving directions (with 지도를 보고), it’s understood as “walk straight.”

Why use 걸어요 instead of 가요 to say “go”?

걸어요 specifically means “walk.” 가요 is more general (“go”). If someone wants you to travel on foot, you choose 걸어요. If mode of transportation doesn’t matter, you might say 지도를 보고 똑바로 가요 instead.

Can I replace -고 with -서? For example, 지도를 보고서 똑바로 걸어요?

Yes. 보고서 or 보고 나서 both emphasize sequence (“after looking at the map”). Differences:
• -고 = simple connector (“and/then”)
• -서 = clear sequence (“after”)
In most spoken contexts, 지도를 보고 똑바로 걸어요 is perfectly fine.

How would I make this instruction more polite or more casual?

You can change the verb ending for different speech levels:
• Casual (반말): 지도 보고 똑바로 걸어.
• Polite (하세요체): 지도 보고 똑바로 걸어요. (the original)
• Honorific/polite (하십시오체): 지도 보고 똑바로 걸으십시오.
• Gentle polite (세요체): 지도 보고 똑바로 걸으세요.

Why is the object marker 를 used in 지도를 보고? Can it be omitted?

In standard Korean, you mark 지도 (map) with the object particle -를: 지도를 보고. In casual speech, Koreans often drop particles: 지도 보고. That’s fine in conversation but less formal.

Is the order 지도를 보고 똑바로 걸어요 fixed? Why is 똑바로 before 걸어요?

In Korean, adverbs (like 똑바로) typically precede the verb they modify. So you’ll normally see 똑바로 걸어요 rather than 걸어요 똑바로. The clause 지도를 보고 comes first to show the sequence: look at the map → walk straight.

Does 지도를 보고 똑바로 걸어요 mean “walk straight while looking at the map”?

It could, but usually it means “look at the map first, then walk straight.” If you want to emphasize simultaneous action (“while looking”), you’d use -면서:
지도를 보면서 똑바로 걸어요.
That clearly says “walk straight as you look at the map.”