In English we say "whenever spring comes, the cherry blossoms bloom" or "if you press the button, the door opens." This sense of automatic, inevitable consequence is exactly what と expresses in Japanese.
How to Connect
Dictionary form / ない form + と
| Pattern | Example |
|---|---|
| Verb dictionary form + と | 押すと |
| Verb ない form + と | 押さないと |
| い-adjective + と | 熱いと |
| な-adjective + だと | 静かだと |
| Noun + だと | バスだと |
Note: と connects to the plain form (not the ます form).
Four Uses
Use 1: Pure Hypothesis — If A, then B
The most basic use, simply expressing a hypothetical condition:
| Japanese | English |
|---|---|
| バスだと30分かかります。 | If you take the bus, it takes 30 minutes. |
| もう少し安いと買うんですが。 | If it were a bit cheaper, I'd buy it. |
Use 2: Sequential Discovery — A happened, then I found B
The first clause describes a completed action; the second describes what was discovered or experienced right after:
| Japanese | English |
|---|---|
| 先生のお宅へ行くと留守でした。 | I went to the teacher's house, and they weren't home. |
| 窓を開けると海が見えた。 | I opened the window, and the sea came into view. |
In this use, the second clause is often in past tense, because it describes what was actually found.
Use 3: Natural Phenomena and Universal Truths
This describes objective laws that are always true — and this is と's exclusive territory. Only と works here:
| Japanese | English |
|---|---|
| 春になると桜が咲く。 | When spring comes, the cherry blossoms bloom. |
| 熱いと汗が出る。 | When it's hot, you sweat. |
| 四月になると花が咲く。 | When April comes, the flowers bloom. |
Natural laws use と because these things inevitably happen every time — no hypothetical "if" needed.
Use 4: Habitual Actions — Every time A, then B
Describes someone's fixed habits or recurring patterns:
| Japanese | English |
|---|---|
| 日本から帰国するとお土産を買ってくれる。 | Every time they come back from Japan, they buy souvenirs. |
| 夜になると散歩に出かける。 | Every evening, they go for a walk. |
The Biggest Restriction: No Volition in the Second Clause
Since と describes inevitable outcomes, the second clause cannot contain commands, requests, invitations, prohibitions, or other expressions of human will:
| Wrong | Correct |
|---|---|
| ❌ 駅に着くと電話してください | ✅ 駅に着いたら電話してください |
| ❌ 暇だと遊びに来てください | ✅ 暇なら遊びに来てください |
If you want someone to do something, don't use と. Use たら for commands/requests, なら for suggestions.
Specifically, と's second clause cannot be:
- Volitional: ～よう, ～つもり
- Imperative: ～なさい, ～しろ
- Request: ～てください
- Prohibition: ～てはいけない
- Invitation: ～ましょう
- Desire: ～たい
How to Tell the Four Uses Apart
Look for two clues:
| Clue | Use |
|---|---|
| Second clause is past tense | Sequential discovery (Use 2) |
| Describes a law of nature or scientific fact | Natural phenomena (Use 3) |
| Means every time | Habitual (Use 4) |
| None of the above | Pure hypothesis (Use 1) |
と vs. Other Conditionals
| と | ば | たら | なら | |
|---|---|---|---|---|
| Natural laws | ✅ Best fit | ○ OK | △ Uncommon | ✗ |
| Habits | ✅ Best fit | ○ | ○ | ✗ |
| Past tense result | ✅ | ✗ | ✅ | ✗ |
| Commands/requests | ✗ | △ | ✅ | ✅ |
| Giving advice | ✗ | △ | ○ | ✅ Best fit |
One rule to remember: と = objective inevitability — no room for personal wishes.
Summary
- と means "whenever A, then B" — describes inevitable relationships
- Four uses: pure hypothesis, sequential discovery, natural phenomena, habits
- Biggest restriction: no volition/commands/requests in the second clause
- Natural phenomena and universal truths — only と works
- Connection: plain form + と (nouns and な-adjectives add だと)
Self-Check
Q1. Fill in the blank: 「春になる＿＿桜が咲く。」
Show answer
と. This is a natural phenomenon — cherry blossoms bloom every spring. Only と works for describing unchanging facts of nature.
Q2. Why can't you say 「駅に着くとタクシーに乗ってください」?
Show answer
Because と cannot have commands or requests in the second clause. 「てください」 is a request, so と is not allowed. Use たら instead: 「駅に着いたらタクシーに乗ってください。」
Q3. In 「先生のお宅へ行くと留守でした」, which use of と is this?
Show answer
Sequential discovery (Use 2). The speaker went to the teacher's house (completed action) and then discovered they weren't home (what was found). The past tense 「でした」 is the giveaway — it describes an actual situation that was encountered.