Learn Hardcore Korean: ije jajeongeoreul tal jul arayo.

Verb stem + -(으)ㄹ (adnominal “to do/going to do” marker) + 줄 (bound noun: “the way/know‑how/fact”) + 알다 (“to know”)
Examples:
- 수영할 줄 알아요. = I know how to swim.
- 운전할 줄 알아요. = I know how to drive.

Why is it 탈 and not 타요 or 타는?

Because in this construction the verb must modify the noun 줄 with the adnominal marker -(으)ㄹ. So 타다 → 탈.

타요 is a finite verb form and cannot directly modify a noun.
타는 줄 changes the meaning: it would be “the fact that (someone) rides,” not “know how to ride.”

What exactly is 줄 here? Doesn’t 줄 mean “line/string”?

Yes, 줄 can mean “line,” but in this grammar it’s a bound noun meaning “the way/know‑how/the fact (of doing something).” It’s similar to other bound nouns like 수, 것, and 법. So 탈 줄 알다 ≈ “know the way/know‑how to ride.”

Should it be 탈 줄 알아요 or 탈 줄을 알아요?

Both are grammatically acceptable. In this idiom, omitting the object particle is more common and natural: 탈 줄 알아요. You may see 줄을 in some styles or for emphasis/clarity, but most learners are taught the particle‑less form.

What’s the difference between -(으)ㄹ 줄 알다 and -(으)ㄹ 수 있다?

-(으)ㄹ 줄 알다: you’ve learned or possess the skill/know‑how.
- 자전거를 탈 줄 알아요. = I know how to ride a bike.
-(으)ㄹ 수 있다: possibility/ability/permission in the given circumstances.
- 자전거를 탈 수 있어요. = I can ride a bike (I’m able/it’s possible/permitted). In many contexts both can work, but only 줄 알다 explicitly means “know how.”

Why does 자전거 take 를?

Because 자전거 is the object of the embedded verb 타다 (“to ride”). Even inside 탈 줄 알다, the original verb’s object is still marked: 자전거를 (탈 줄) 알아요.

Can I drop 를 and say 자전거 탈 줄 알아요?

Yes, in casual speech object particles are often dropped, and 자전거 탈 줄 알아요 is common. In careful/formal writing, keeping 를 is safer: 자전거를 탈 줄 알아요.

Who is the subject here? There’s no “I.”

Korean often omits the subject when it’s clear from context. Here, the subject is understood (usually “I”). You can add it for clarity:

저는 이제 자전거를 탈 줄 알아요.

What nuance does 이제 add? How is it different from 지금?

이제 = “now (as of now), from now on,” often implying a change from the past.
- Here it suggests you couldn’t before, but now you can.
지금 = “right now/at this moment,” focusing on the present time point without the change‑of‑state nuance.

What politeness level is 알아요, and what are other options?

알아요 is polite informal (해요체), the default for most situations. Variants:

Casual: 알아
Polite formal: 압니다
Honorific (to show respect to the subject): 아세요 (e.g., 탈 줄 아세요?)

Any pronunciation tips for the whole sentence?

이제: [이제]
자전거를: the 를 is light; the phrase flows as [자전거를] without strong stress.
탈 줄: links smoothly as [탈줄].
줄 알아요: liaison makes it sound like [주라라요] (the final ㄹ of 줄 links to the following vowel of 알아요). Say it smoothly as one rhythm group: [이제 자전거를 탈줄 아라요].

Is the spacing correct? Why not 탈줄 or 줄알아요?

Correct spacing is:

탈 줄 (bound noun 줄 is spaced from the verb modifier)
줄 알아요 (verb 알다 is separate) So: 이제 자전거를 탈 줄 알아요, not 탈줄 or 줄알아요.

Can I say 타는 법을 알아요 instead? Is there a nuance difference?

Yes: 자전거 타는 법을 알아요 also means “I know how to ride a bike.”

줄 알다 feels a bit more idiomatic and compact for “know how.”
법 (“method”) explicitly frames it as knowing the method/technique.

If I just say 자전거를 타요, does it mean the same thing?

Not exactly. 자전거를 타요 means “I ride a bike (now/usually).” It doesn’t explicitly say you learned the skill. But as a short answer to “Do you know how to ride?” it’s natural to reply 네, (자전거) 타요.

How do I say I don’t know how (or didn’t use to know how)?

Present: 자전거를 탈 줄 몰라요. = I don’t know how to ride a bike.
Past: 예전엔 자전거를 탈 줄 몰랐어요. = I didn’t know how before.
Change of state: 이제 자전거를 탈 줄 알게 됐어요. = I’ve come to learn how now.

Is there any pitfall if I write 타 줄 알아요 (without the ㄹ)?

Yes. 타 줄 is parsed as 타 주다 (“to do the riding for someone”), meaning “ride (for someone).” For “know how,” you must include -(으)ㄹ: 탈 줄 알아요.

Can I say 이제는 instead of 이제?

Yes. 이제는 adds a stronger contrastive nuance (“now, as opposed to before/other times”):

이제는 자전거를 탈 줄 알아요. feels slightly more contrastive/emphatic than 이제.

Any quick alternatives to express ability or skill here?

자전거를 탈 수 있어요. = I can ride a bike.
자전거를 잘 타요. = I ride a bike well. (Implies skill, not just know‑how)
자전거를 배웠어요. = I learned (how to) ride a bike.