LESSON NOTES · レッスンノート

N4Lesson notes · Oct 4, 2026

Crowded in Japanese: 混こんでる (こんでる) and 空あいてる

Crowded in Japanese is 混こんでいる (こんでいる), almost always shortened to 混こんでる (こんでる) in speech — and its opposite, "not crowded", is 空あいてる (すいてる).

English has one adjective, "crowded". Japanese uses a verb instead. 混こむ (こむ) means "to become crowded", and you describe the current state with the ている form. Once you see why, the whole word family (混雑こんざつ, 満員まんいん, ぎゅうぎゅう) sorts itself out by register and degree.

The basics

Why is it 混こんでいる and not just 混こむ?

Because 混こむ is an action verb ("to get crowded"), and what you want to say is that a place is in the state of being crowded right now. The ている form describes exactly that: a change has happened and its result is still there.

今日きょうは電車でんしゃが混こんでいる。 — The train is crowded today. (plain form, written or thoughtful speech) この店みせ、混こんでるね。 — This place is crowded, isn't it. (casual, the い of ている dropped)

If the ている form is new to you, our guide to 〜ている as progressive and state explains the two meanings. 混こんでいる is the "state" kind. It is similar to how 知しっている means "I know", not "I am knowing". Saying 混こむ on its own usually means "it tends to get crowded" or "it will get crowded".

この道みちは朝あさよく混こむ。 — This road often gets crowded in the morning. (plain form, a habit)

How do you say "not crowded"?

Use 空あいている (すいている), shortened to 空あいてる (すいてる). It means "there is room, not many people".

平日へいじつは空あいてるよ。 — It's not crowded on weekdays. (casual, friendly tip) この電車でんしゃは空あいていますね。 — This train isn't crowded, is it. (polite)

You can also say 混こんでいない or, in speech, 混こんでない. Both are natural. 空あいてる (空あいている) is just more pointed: it says the place has room, not only that it is not full.

Is 空あいてる "empty" or "vacant"? The two readings of 空そら

The same kanji 空あく has two readings, and the meaning shifts with them.

  • すく (すいている) — not crowded, not many people. The room is spacious.
  • あく (あいている) — vacant, free, open. A specific slot or seat is available.

お店みせが空あいている。 — The shop isn't crowded. (read すいている) 席せきが空あいていますか。 — Is there a free seat? (read あいて. Asking if a specific seat is open)

The kanji is the same, so you cannot tell from text alone. Context decides. 席せきが空あいている is about a specific seat, while 電車でんしゃが空あいている is about the overall crowd level. Learners often assume there is one reading, which is where confusion starts. Related verbs also show up in pairs, which is a topic we cover in transitive and intransitive verbs.

How do you ask "Is it crowded?" at a restaurant?

Say 混こんでますか。 (polite: 混こんでいますか). It is the everyday question at a restaurant door or when calling ahead.

今いま、混こんでますか。 — Is it crowded right now? (polite, standard) 何名なんめい様さまですか。 — How many people? (polite, what the staff will say next)

If staff answer 今いまは空あいてますよ, you can walk in. If they say 少すこし混こんでいます, you may have to wait.

Beyond the basics

What is 混雑こんざつ, and when does it appear?

混雑こんざつ (こんざつ) is the formal noun for "congestion". You see it on signs, in station announcements and in news. You rarely use it in casual chat.

ただいま、車内しゃないが大変たいへん混雑こんざつしております。 — The train is very crowded right now. (very formal, announcement style) 混雑こんざつが予想よそうされます。 — Crowding is expected. (formal, news and notices)

In everyday speech, people say 混こんでる. In a notice, they write 混雑こんざつ. If you work through the 混こむ family, you will often meet verbs like 混雑こんざつする (to be congested) in written Japanese too.

What is the difference between 満員まんいん and 混こんでる?

満員まんいん (まんいん) means "full", literally "full of members". It is the highest degree: every seat or space is taken. It sounds like a fact about capacity, not a feeling.

満員電車まんいんでんしゃに乗のりたくない。 — I don't want to ride a packed train. (casual, a famous complaint) この映画館えいがかんは満員まんいんだった。 — The cinema was full. (plain form, past) 満員御礼まんいんおんれい — Full house, thank you. (on a sign or banner, a sold-out event)

満員電車まんいんでんしゃ (まんいんでんしゃ) is the standard phrase for a rush-hour train full of standing passengers. 満員まんいん also works for theaters, concerts, buses and elevators. 満員まんいん counts room for people only, so bread that has run out is 売り切うりきれ instead, a split that 満員まんいん vs 売り切うりきれ shows with sold-out tickets as well.

What are ぎゅうぎゅう and 人ひとが多おおい?

ぎゅうぎゅう is a mimetic word for being squeezed together. It adds a physical feeling, and it is casual.

電車でんしゃがぎゅうぎゅうだった。 — The train was jammed. (casual, vivid, you could feel the squeeze) エレベーターにぎゅうぎゅう詰つめで乗のった。 — We were crammed into the elevator. (casual)

人ひとが多おおい (ひとがおおい) means "there are many people". It is plain and neutral, and often used for places like a street or a festival.

今日きょうは人ひとが多おおいね。 — There are a lot of people today. (casual, observing a crowd)

人ひとが多おおい describes the number of people. 混こんでる describes the inconvenience: you can't move, you have to wait. A wide quiet park can have 人ひとが多おおい without being 混こんでる.

How does it sound in anime?

Anime uses these words for comic timing. A character getting squeezed on a train says ぎゅうぎゅうだよ! Characters at a festival groan 人ひとが多おおすぎる! And a shop or event drawing a huge crowd gets 満員まんいん or 大混雑だいこんざつ in the narration. A character who hates crowds will mutter 混こんでるなあ... with a sigh on the なあ.

うわ、すごく混こんでる! — Wow, it's so crowded! (casual, surprised) 今日きょうはどこも混こんでるなあ。 — Everywhere is crowded today, huh. (casual, resigned)

Is it 混こむ or 込こむ? Which kanji do I write?

Both kanji exist, and you will see both. 混こむ is the usual spelling for "to be crowded" in modern writing. 込こむ appears in a few fixed words such as 人込ひとごみ (ひとごみ, a crowd) and 込こみ合あう (こみあう, to be crowded). If you are unsure, 混こむ is the safe choice for the plain verb. The reading is こむ either way.

Common mistakes

  • Saying 混こむ to mean "it is crowded now". 混こむ on its own sounds like a habit or a future event. For the present state, use 混こんでいる or 混こんでる.
  • Using 混雑こんざつしてる in casual talk. It is grammatical, but it sounds like a news report. With friends, 混こんでる is natural.
  • Confusing the two readings of 空あく. 席せきが空あいてる (あいてる) means a seat is free. 店みせが空あいてる (すいてる) means the shop is not busy. Same kanji, different readings.
  • Using 満員まんいん for "a little crowded". 満員まんいん means full. For "somewhat crowded", say ちょっと混こんでる.
  • Saying 人ひとが多おおい when you mean the place is hard to use. 人ひとが多おおい only counts people. 混こんでる adds the sense that it is hard to move or find a seat.

A quick comparison

Word Reading Feel Example
混こんでる こんでる Everyday, crowded この店みせ、混こんでるね
空あいてる すいてる Everyday, not crowded 平日へいじつは空あいてるよ
空あいている (seat) あいている Free, vacant 席せきが空あいていますか
混雑こんざつ こんざつ Formal, signs and news 混雑こんざつが予想よそうされます
満員まんいん まんいん Full, at capacity 満員電車まんいんでんしゃ
ぎゅうぎゅう ぎゅうぎゅう Casual, squeezed 電車でんしゃがぎゅうぎゅうだった
人ひとが多おおい ひとがおおい Neutral, many people 今日きょうは人ひとが多おおいね

For another pair of everyday words, see now in Japanese: 今いま (いま), which is handy for asking 今いま、混こんでますか.

Practice

Work out each answer first. Questions 4 and 5 are a pair — the same kanji with two readings.

1. Say "This place is crowded, isn't it" in casual Japanese.

Show answer

この店みせ、混こんでるね — 混こんでいる with the い dropped, plus ね for shared feeling.

2. Why do we say 混こんでいる and not 混こむ for "it is crowded now"?

Show answer

Because 混こむ is an action ("get crowded") — the ている form describes the state that results. 混こむ alone sounds like a habit or a future event.

3. Say "It's not crowded on weekdays" in casual Japanese.

Show answer

平日へいじつは空あいてるよ — 空あいてる (すいてる) is the natural opposite of 混こんでる.

4. You want to ask if a specific seat is free. How do you say it, and how do you read 空あい?

Show answer

席せきが空あいていますか (あいて) — あく means vacant or free, a specific slot.

5. A cafe is quiet with few customers. How do you say "The cafe isn't crowded", and how do you read 空あい?

Show answer

カフェが空あいている (すいて) — すく means "not crowded". Same kanji as question 4, different reading.

6. You are at a restaurant door. Ask politely, "Is it crowded right now?"

Show answer

今いま、混こんでますか — the standard polite question. 混こんでいますか is slightly more careful.

7. Which word appears in a station announcement: 混こんでる or 混雑こんざつ?

Show answer

混雑こんざつ — it is the formal noun, used on signs and in announcements. 混こんでる is for speech.

8. The train is so full that everyone is standing and squeezed. Which word shows the highest degree?

Show answer

満員まんいん — 満員電車まんいんでんしゃ means a train at capacity. ぎゅうぎゅう is the casual, physical way to say the same scene.

9. A big park has many people but plenty of space. Is it 人ひとが多おおい or 混こんでる?

Show answer

人ひとが多おおい — it counts people. 混こんでる adds the feeling that it is hard to move or find a seat.

10. Which spelling is the safe default for the plain verb: 混こむ or 込こむ?

Show answer

混こむ — 込こむ appears mainly in fixed words like 人込ひとごみ and 込こみ合あう.

During a trial lesson, complain about a packed train and ask whether a café is 空あいてる, until 混こんでる and 満員まんいん come out without thinking.

FAQ

Is 混こんでる the same as 混こんでいる? Yes. 混こんでる is the casual spoken form, with the い dropped. 混こんでいる is the fuller form, used in writing and careful speech.

How do I say "very crowded"? Put すごく or とても before 混こんでる: すごく混こんでる. For a more extreme degree, use 満員まんいん or ぎゅうぎゅう.

Is 空あいてる read あいてる or すいてる? Both exist. すいてる means "not crowded" and あいてる means "vacant, free". Context decides: a shop or a train is すいてる, while a seat or a room is あいてる.

What do I say if I want to avoid crowds? 何時なんじごろが空あいていますか — "What time is it not crowded?" is a polite way to ask staff.

Is 混雑こんざつ a verb? It is a noun, and 混雑こんざつする is the verb form, "to be congested". It sounds formal, so use 混こんでる in conversation.

Is 満員電車まんいんでんしゃ only for trains? No. 満員まんいん means full of people, so it also works for a bus, a cinema, an elevator or a concert hall.

Vocabulary from this article

Tap the block to select all of it, then copy. In Anki: File → Import, note type Basic, separator Tab — the first column becomes the front, the second the back.

混む	こむ — to get crowded
混んでいる	こんでいる — to be crowded (state)
空いている	すいている — to be not crowded
空いている	あいている — to be vacant, free (seat)
混雑	こんざつ — congestion (formal)
満員	まんいん — full, at capacity
満員電車	まんいんでんしゃ — packed train
ぎゅうぎゅう	ぎゅうぎゅう — squeezed together
人が多い	ひとがおおい — there are many people
席	せき — seat
電車	でんしゃ — train
平日	へいじつ — weekday
人込み	ひとごみ — a crowd

I'm Yuuki, a Japanese teacher based in Tokyo. I've taught on italki as a Top 1% teacher and watched over 1,500 anime, so most of the example sentences on this blog come from lines I've actually heard students ask about — including this one, which comes up in nearly every beginner's first few lessons. For practice with feedback, Book a trial lesson · $13, or work through Japanese practice exercises first.

Sources: the author's own lessons and standard reference grammars.

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