Learn Hardcore Korean: jigeum hoengdanbodoreul geonneogo isseoyo.

-고 있다 is the Korean way to express the progressive aspect (“be …-ing”). You attach -고 to the verb stem (건너-) and then conjugate 있다 politely as 있어요. So 건너고 있어요 means “I am crossing.”

Why is 지금 included at the beginning? Can I omit it?

지금 means “now” and emphasizes that the action is happening at this very moment. You can omit it—횡단보도를 건너고 있어요 still means “I’m crossing the crosswalk”—but without 지금 you lose the extra sense of immediacy.

Why do we use -를 after 횡단보도 in 횡단보도를 건너고 있어요?

-를 is the object-marking particle. It shows that 횡단보도 is the direct object of the action 건너다 (“to cross”). In other words, it tells us what is being crossed.

How do you pronounce 횡단보도?

The standard romanization is hwang-dan-bo-do. Due to sound assimilation, it often comes out like [행단보도] with an “ng” sound sliding into the “d.” Break it into four syllables: 횡-단-보-도.

Why is 건너다 the verb here? Could I use another verb for “cross”?

건너다 specifically means “to cross (over something)”—roads, rivers, bridges, etc. Other verbs like 지나가다 mean “to pass by” and wouldn’t convey the idea of going from one side to the other.

Can I say 지금 횡단보도를 건너는 중이에요 instead of -고 있어요?

Yes. 건너는 중이에요 also marks the progressive (“in the middle of crossing”). It’s slightly more formal or written in style, whereas 건너고 있어요 is the everyday spoken form.

How would I make this sentence more formal or official?

Switch to the formal ending -고 있습니다. For example:

지금 횡단보도를 건너고 있습니다.
You’ll often hear this in announcements or news reports.

Could I say 횡단보도로 건너고 있어요 instead of using -를?

No. -로/으로 marks direction or means (“by/with”), not the object. Saying 횡단보도로 건너다 would imply “cross by/using the crosswalk,” which isn’t standard for “I am crossing the crosswalk.” Use -를 to mark the thing being crossed.

Can I replace 횡단보도 with 길 to say “I’m crossing the street”?

Yes. 길을 건너고 있어요 means “I’m crossing the street,” but it’s more general. 횡단보도 specifically refers to the marked crosswalk on the road.