Learn Hardcore Korean: keikeu jogageun myeot gaeyeyo?

은 is the topic marker. It tells the listener, “Today we’re talking about cake pieces.” You could also use the subject marker 이 (케이크 조각이 몇 개예요?), but 은 shifts the nuance to “as for cake pieces…” and often emphasizes contrast or the theme of the sentence.

Why do we use the counter 개 after 몇?

Korean requires a counter (or classifier) when counting discrete items. 개 is the most general counter for objects. So when you ask “how many pieces,” you say 몇 개 rather than just 몇. If you were counting sheets of paper, you’d use 장, for bottles 병, etc.

Why is the copula 예요 used instead of 이에요 or 입니다?

Use 예요 when the preceding noun ends in a vowel (like 개).
Use 이에요 when the noun ends in a consonant (e.g. 책이에요).
입니다 is a more formal (deferential) copula. So 몇 개입니까? would be the formal equivalent of 몇 개예요?

How do you pronounce 몇 개 correctly?

In IPA it’s [mjʌt̚.kɛ], often heard as 멷개. The final ㅅ in 몇 is an unreleased [t̚], so you’ll feel the tongue tap the roof of the mouth but not release before moving on to 개.

Could I instead say 케이크는 몇 조각이에요?

Yes. Here 조각 acts as both “piece” and counter, so 몇 조각이에요? also means “How many pieces of cake are there?” Using 몇 개예요? is more general, while 몇 조각이에요? specifically uses the noun “piece.”

What’s the difference between 케이크 조각은 and 케이크는?

케이크 조각은: “As for cake pieces…”—you focus on the pieces themselves.
케이크는: “As for the cake…”—you’d then ask 몇 조각이에요? to indicate “How many pieces does the cake have?” The topic changes from the pieces to the whole cake.

Can I drop the topic marker and just say 케이크 조각 몇 개예요?

In casual spoken Korean, yes. Omitting 은/는/이/가 is common when context is clear:
“케이크 조각 몇 개예요?”
It’s less grammatically “complete” but perfectly natural in everyday conversation.

Why is 몇 used instead of 얼마나?

몇 asks “how many” for countable items.
얼마나 asks “how much” in terms of degree or amount (often uncountable).
Since you’re counting discrete pieces, you use 몇.

What level of politeness does 예요 represent?

예요 is polite, informal speech (해요체). You’d use it with strangers, acquaintances, or anyone you’re not close enough to speak casually to.

How would you break down 케이크 조각은 몇 개예요? word by word?

케이크 (cake)
조각 (piece)
은 (topic marker)
몇 (how many)
개 (counter for items)
예요 (polite copula “is/are”)