Grammar Rule in 30 Seconds
Use 'across' for flat surfaces and 'through' for three-dimensional spaces or volumes.
- Use 'across' for 2D surfaces like roads or bridges: 'I ran across the street.'
- Use 'through' for 3D spaces like tunnels or forests: 'I walked through the woods.'
- Use 'across' for the other side: 'He lives across the river.'
Overview
across と through は、日本語に訳すとどちらも「〜を横切って」「〜を通って」といった似たような言葉になってしまうため、混乱を招きやすい表現です。しかし、ネイティブスピーカーの頭の中では、この2つの単語は全く異なる「空間のイメージ」を持っています。across は「平面的な広がり」を移動するイメージ、through は「立体的な空間や障害物の中」を通り抜けるイメージです。このセクションでは、この2つの前置詞が持つ根本的な違いを、日本人の言語感覚と比較しながら、ビジネスや日常生活で使えるレベルまで深く掘り下げて解説していきます。通勤電車の中や、カフェでのちょっとした時間に、この「空間感覚」をマスターして、表現の幅を広げていきましょう。across と through の違いを理解するために、まずはそれぞれのコア・イメージを掴みましょう。across の核となるイメージは、ある領域の「端から端まで」を、平面的な表面に沿って移動することです。日本語の「〜を横断する」「〜の向こう側へ」という感覚に近いです。- 2次元的な視点: 地図を上から見ているような、平らな場所での移動を指します。
- 境界線を越える: 道路のこちら側からあちら側へ、川の左岸から右岸へというように、境界を越えるニュアンスが強いです。
- 遮るものがない: 基本的に、移動の邪魔になるような立体的な障害物が「中」にあることは想定していません。
through の核となるイメージは、3次元的な空間の「中」に入り、そこを通り抜けて反対側に出ることです。日本語の「〜を貫通する」「〜の中を突っ切る」という感覚です。- 3次元的な視点: 周囲を壁や木々、人混みなどに囲まれた空間の中を進むイメージです。
- 経験とプロセス: 空間の内部を通過するため、その中にあるものを経験したり、影響を受けたりするニュアンスが含まれます。
- 入り口と出口: トンネルのように、明確な「入り口」から入り、「出口」から出るという一連の流れを強調します。
across と through は前置詞ですので、基本的には 動詞 + 前置詞 + 名詞句 という形で使われます。この時、後に続く名詞が「平面」として捉えられているか、「立体的な空間」として捉えられているかによって、前置詞が決まります。walk across the street（通りを横切って歩く）swim across the river（川を泳いで渡る）drive across the desert（砂漠を車で横断する）
walk through the park（公園の中を通り抜けて歩く）drive through the tunnel（トンネルを車で通り抜ける）look through the window（窓越しに中を見る）
go, run, fly, move など）だけでなく、視線や情報の伝達を表す動詞とも頻繁に使われます。- 視線:
look across the room（部屋の端から端まで見渡す） vslook through the telescope（望遠鏡の中を覗き込む） - 情報の伝達:
spread across the world（世界中に広がる：表面的な広がり） vsget through the message（メッセージを伝える：障害を乗り越えて届けるニュアンス）
- Across を使う場合:
walk across the park です。これは、公園を一つの「面」として捉えています。- Through を使う場合:
walk through the park です。これは、公園を木々や空気に囲まれた「立体的な空間」として捉えています。- Across:
The bridge across the river.（川にかかる橋）- Through:
The water flows through the pipe.（水がパイプの中を流れる）- Across (広がり):
The company has offices across Asia.（その会社はアジア全域にオフィスがある）- Through (継続・完了):
We worked through the night.（私たちは一晩中働いた）get through a difficult time（困難な時期を乗り越える）のように、辛い経験という「中」を通り抜けて出口に到達するという文脈でも使われます。through には「〜を介して」という手段の意味もあります。これは、情報がある媒体の中を通って自分に届くイメージです。I found out about the job through a friend.（友人を介してその仕事のことを知った）
cross（動詞）と across（前置詞）の混同I across the street. と言ってしまう人がいますが、これは間違いです。- ❌ Wrong:
I across the street. - ✅ Correct:
I walk across the street.またはI cross the street.
across はあくまで前置詞（または副詞）なので、必ず動詞と一緒に使うか、cross という動詞そのものを使う必要があります。across を使ってしまうwalk across the tunnel と言ってしまうことがあります。しかし、トンネルは壁に囲まれた3次元の筒状の空間です。囲まれている場所には必ず through を使いましょう。- ❌ Wrong:
The train goes across the tunnel. - ✅ Correct:
The train goes through the tunnel.
through で訳してしまうthrough は不自然です。- ❌ Wrong:
I go to school through the bridge. - ✅ Correct:
I go to school across the bridge.
through the bridge と言うと、橋の構造体の中（鉄骨の間など）を通り抜けているような、スパイ映画のような描写になってしまいます。across や through と混同しやすい他の前置詞と比較してみましょう。- Across: 表面をなぞるように移動する（2次元）。
- Over: 何かの上を飛び越える、あるいは覆いかぶさるように移動する（弧を描くイメージ）。
walk across the road（道を歩いて渡る）jump over the wall（壁を飛び越える）
- Through: その媒体の「中」を通過する感覚が強い。
- Via: 経由地や特定のルートを指す、より事務的・地理的な言葉。主に交通機関や通信経路に使われます。
I went to London via Paris.（パリ経由でロンドンへ行った）I sent the file via email.（メールでファイルを送った：through emailも使われますが、viaの方が一般的です）
across the river と through the river はどう使い分けますか？across the river（泳いで、またはボートで向こう岸へ渡る）を使います。しかし、もし川が浅くて、水の中に足を入れてジャブジャブと「水という媒体の中を」歩いて進む場合は、walk through the river と言うことができます。状況によって使い分けられるのです。all across the country と all through the country は同じですか？all across the country は、国のあちこち（表面上の至る所）に広がっている様子を強調します（例：店舗の展開など）。all through the country は、その国の中を旅して回ったというプロセスや、隅々まで浸透している様子を強調します。read through という表現をよく聞きますが、read across はありますか？read through は「最初から最後まで通読する」という意味で非常によく使われます。これは本を一つの「道のり」や「空間」と捉え、その中を入り口から出口まで通り抜けるイメージです。一方、read across という表現は一般的ではありません。ただし、複数の資料を横断的に読み比べることを read across different sources と言うことはありますが、かなり専門的な表現になります。We talked through the issue.（その問題について徹底的に話し合った）という表現がよく使われます。問題という「森」の中に分け入り、出口が見えるまで（解決するまで）議論を尽くした、というニュアンスになります。across はこの文脈では使いません。Usage with Common Verbs
| Verb | With 'Across' (Surface) | With 'Through' (Volume) |
|---|---|---|
|
Walk
|
Walk across the bridge
|
Walk through the forest
|
|
Run
|
Run across the track
|
Run through the tunnel
|
|
Drive
|
Drive across the border
|
Drive through the city
|
|
Swim
|
Swim across the lake
|
Swim through the reeds
|
|
Look
|
Look across the valley
|
Look through the telescope
|
|
Cut
|
Cut across the grass
|
Cut through the meat
|
|
Fly
|
Fly across the ocean
|
Fly through the clouds
|
|
Pass
|
Pass across the screen
|
Pass through the gate
|
Meanings
These prepositions describe movement from one side of something to the other, but they differ based on the geometry of the object being crossed.
Across: Surface Movement
Movement from one side to the other of a flat area, surface, or line.
“The cat ran across the lawn.”
“They are building a new bridge across the bay.”
Through: Volume Movement
Movement from one side to the other within a three-dimensional space, often surrounded by things.
“The train went through the tunnel.”
“Water flows through the pipes.”
Across: Position
On the opposite side of something.
“The pharmacy is just across the road.”
“She sat across from me at dinner.”
Through: Time and Process
From the beginning to the end of a period or a series of actions.
“He slept through the entire movie.”
“I read through the contract carefully.”
Reference Table
| Function | Preposition | Example |
|---|---|---|
|
Movement (2D)
|
Across
|
He ran across the playground.
|
|
Movement (3D)
|
Through
|
The mouse ran through the pipe.
|
|
Position
|
Across
|
The bank is across the street.
|
|
Duration
|
Through
|
She worked through the weekend.
|
|
Medium
|
Through
|
I heard it through the grapevine.
|
|
Distribution
|
Across
|
The policy applies across the firm.
|
|
Completion
|
Through
|
I am halfway through the book.
|
|
Obstacle
|
Through
|
We pushed through the heavy snow.
|
フォーマル度スペクトル
The pedestrians traversed across the municipal park. (Daily life)
They walked across the park. (Daily life)
They cut across the park. (Daily life)
They headed across the park. (Daily life)
2D vs 3D Movement
Which one should I use?
Is it a flat surface?
Are you inside it?
レベル別の例文
I walk across the road.
The cat goes through the window.
He lives across the street.
We go through the park.
She ran across the bridge to catch the bus.
The bird flew through the open door.
They walked across the big field.
I can't see through these dirty glasses.
We sailed across the Atlantic Ocean in three weeks.
The sunlight shone through the leaves of the trees.
I found this old photo while looking through a drawer.
News of the accident spread quickly across the town.
The company has offices scattered across the country.
He managed to get through the exam despite being ill.
The bullet passed through the wooden plank.
She stared across the room at her rival.
The virus spread across the population with alarming speed.
I've been through a lot of emotional turmoil lately.
The architect designed a path that cuts across the courtyard.
He spoke through an interpreter during the summit.
The theme of redemption resonates across his entire body of work.
We must see this initiative through to its logical conclusion.
The signal was transmitted across a series of relay stations.
She navigated through the labyrinthine bureaucracy of the ministry.
間違えやすい
Both can mean moving to the other side of a road or river.
Learners use 'through' when they mean following a path.
Learners forget the 'from' when describing location.
よくある間違い
I go across the door.
I go through the door.
The car goes through the bridge.
The car goes across the bridge.
I walk through the street.
I walk across the street.
He is through the room.
He is across the room.
We walked across the woods.
We walked through the woods.
The bird flew across the window.
The bird flew through the window.
I looked across the keyhole.
I looked through the keyhole.
I slept across the meeting.
I slept through the meeting.
The news went through the country.
The news went across the country.
He pushed across the crowd.
He pushed through the crowd.
The idea spread through the board.
The idea spread across the board.
文型パターン
I walked across the ___.
The train went through the ___.
It's located just across from the ___.
I've been looking through my ___ all morning.
Real World Usage
Drive across the bridge and then go through the tunnel.
I was scrolling through my Instagram feed.
I have worked with teams across different time zones.
We backpacked through Europe last summer.
Let's walk through the project requirements.
I'm halfway through the movie, call u later!
The Paper vs. Box Test
Avoid 'Acrosst'
Through for Time
Across from vs Opposite
Smart Tips
Check if you are 'on top' of the thing (Across) or 'inside' the thing (Through).
Always use 'across from' if you are describing where a building is.
Use 'through' because you are moving from the first page to the last page (a volume of work).
Use 'across' to show distribution, like a blanket covering a bed.
発音
Across Ending
The 'ss' in across is a voiceless /s/ sound. Do not add a 't' at the end (a common native-speaker error: 'acrosst').
Through Vowel
The 'ough' is pronounced like 'oo' in 'food'. The 'th' is the voiceless /θ/ as in 'think'.
Emphasis on Preposition
I didn't go OVER it, I went THROUGH it!
Used to correct a misunderstanding about the path taken.
暗記しよう
記憶術
Across is for an Area (flat); Through is for a Tunnel (3D).
視覚的連想
Imagine a flat sheet of paper. To get to the other side, you go 'across'. Now imagine a straw. To get to the other side, you must go 'through'.
Rhyme
Across the floor, through the door.
Story
A hiker wanted to reach a mountain. First, he walked across a flat desert (2D). Then, he had to hike through a thick, dark forest (3D). Finally, he swam across a wide river (2D) to reach the base.
Word Web
チャレンジ
Look around your room. Identify one thing you can move 'across' (like a rug) and one thing you can move 'through' (like a doorway). Say the sentences out loud.
文化メモ
In the UK, 'across from' is often replaced by 'opposite'. For example, 'The pub is opposite the station.'
Americans almost exclusively use 'across from' for locations. 'The store is across from the mall.'
Similar to British English, but 'across' is frequently used in sports commentary to describe the movement of the ball over the field.
'Across' comes from the 13th-century Old French 'a croix', meaning 'in the form of a cross'. 'Through' comes from the Old English 'thurh', which has Proto-Germanic roots.
会話のきっかけ
Have you ever walked across a very long bridge?
What is the most beautiful forest you have ever walked through?
If you had to travel across the ocean, would you prefer a ship or a plane?
Tell me about a difficult time you've been through recently.
日記のテーマ
よくある間違い
Test Yourself
The hikers walked ___ the thick forest for three hours.
He drew a line ___ the middle of the page.
Find and fix the mistake:
The train passed across the tunnel at high speed.
Match each item on the left with its pair on the right:
lives / she / the / street / across
We use 'through' for flat surfaces like a map.
A: How do I get to the bank? B: Just walk ___ the bridge and it's on your left.
1. A pipe, 2. A lake, 3. A window, 4. A field
Score: /8
練習問題
8 exercisesThe hikers walked ___ the thick forest for three hours.
He drew a line ___ the middle of the page.
Find and fix the mistake:
The train passed across the tunnel at high speed.
1. Bridge, 2. Tunnel, 3. Crowd, 4. Desert
lives / she / the / street / across
We use 'through' for flat surfaces like a map.
A: How do I get to the bank? B: Just walk ___ the bridge and it's on your left.
1. A pipe, 2. A lake, 3. A window, 4. A field
Score: /8
Practice Bank
12 exercisesThe hikers made their way ___ the narrow canyon.
A snake was slithering ___ the grass.
Select the correct sentence:
The nail went across the piece of wood.
Translate this idea into English: 'The wind blew among the trees.'
Arrange these words:
Match the action to its most likely location:
I'm just looking ___ the window at the people walking by.
She's had to go across a lot of difficulties this year.
Arrange these words:
Which sentence suggests a more complete action?
Translate this idea into English: 'I drew a line on the paper, from one side to the other.'
Score: /12
よくある質問 (8)
Yes! If you feel like the park is a 3D space with trees and gates around you, `through` is very common. If you are just crossing it to get to the other side, `across` is also fine.
Yes, they are synonyms. `Across from` is more common in American English, while `opposite` is more common in British English.
This is a metaphorical use of `through` for time. We imagine time as a tunnel or a path that we are moving inside of from start to finish.
Yes. In the sentence 'The river is wide, I can't swim across,' `across` is an adverb because it doesn't have a noun following it.
It is an idiom meaning 'applying to everyone or everything in a group.' For example, 'The company gave a 5% raise across the board.'
Only if the bridge is enclosed (like a covered bridge or a tunnel-like structure). Otherwise, use `across`.
`Thru` is an informal, American spelling often used on road signs or in fast-food 'drive-thrus'. In formal writing, always use `through`.
`Throughout` is more emphatic and means 'in every part of' or 'during the whole time of'.
Scaffolded Practice
1
2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
a través de / por
English requires a choice based on 2D/3D, while Spanish often relies on the verb choice.
à travers / par
French speakers often struggle with 'across' as a preposition because they prefer the verb 'traverser'.
über / durch
German 'über' also means 'above', which can lead to confusion with 'over'.
を渡る (wo wataru) / を通る (wo tooru)
Japanese encodes the movement in the verb rather than just the preposition.
عبر (abra) / خلال (khilal)
Arabic 'abra' is more versatile and less strictly 2D/3D than English.
过 (guò) / 穿过 (chuānguò)
Chinese uses verb-complements to show the nature of the movement.
Learning Path
Prerequisites
関連動画
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