Meaning & Usage
The 〜たら form is likely the most useful conditional you will learn in Japanese. It describes a simple sequence: once the first action (the "if" part) is finished, the second action occurs. While English speakers often distinguish between "if" and "when," 〜たら covers both concepts depending on the context.
Think of it as the "past-tense conditional." Because it is built from the た (ta) form, it carries a strong sense that Action A must be completed before Action B can happen. This emphasis on completion is what sets it apart from other conditionals like 〜と or 〜ば.
One reason learners love 〜たら is its flexibility. You can use it in casual or polite settings without sounding too stiff. It works perfectly for giving advice, making requests, or expressing personal intentions. Whether you are talking about a hypothetical lottery win or just what you'll do after work, 〜たら is usually your best choice.
Finally, this grammar point has a special use called "discovery." When used in the past tense, it describes doing something and then noticing something unexpected. For example, if you say "When I opened the door, a cat ran out," you would use 〜たら to show that the second event was a surprise result of the first action.
Structure & Formation
To form 〜たら, start with the plain past tense (Ta-form) of any verb, adjective, or noun, and simply add ら.
| Word Type | Formation Rule | Plain Past | Conditional (たら) |
|---|---|---|---|
| Verb | Ta-form + ら | 食べた | 食べたら |
| I-Adjective | Drop 〜い, add 〜かったら | 安かった | 安かったら |
| Na-Adjective | Root + だったら | 暇だった | 暇だったら |
| Noun | Noun + だったら | 雨だった | 雨だったら |
For negative forms, follow the same logic. Change 行かない (don't go) to 行かなかった (didn't go), then add ら to get 行かなかったら (if I don't go).
Example Sentences
1. Hypothetical Conditions (If)
明日、雨が降ったら、家にいます。
ashita, ame ga futtara, ie ni imasu.
If it rains tomorrow, I will stay at home.
お金がたくさんあったら、新しい車を買いたいです。
okane ga takusan attara, atarashii kuruma wo kaitai desu.
If I had a lot of money, I would want to buy a new car.
パソコンの使い方がわからなかったら、聞いてください。
pasokon no tsukaikata ga wakaranakattara, kiite kudasai.
If you don't know how to use the computer, please ask.
2. Temporal Sequences (When / After)
仕事が終わったら、飲みに行きましょう。
shigoto ga owattara, nomi ni ikimashou.
When work finishes, let's go out for a drink.
駅に着いたら、電話をしてください。
eki ni tsuitara, denwa wo shite kudasai.
Once you arrive at the station, please call me.
２０歳になったら、お酒を飲むことができます。
nijissai ni nattara, osake wo nomu koto ga dekimasu.
When you turn 20 years old, you can drink alcohol.
3. Advice and Suggestions
気分が悪かったら、すぐに休んだほうがいいですよ。
kibun ga warukattara, sugu ni yasunda hou ga ii desu yo.
If you feel unwell, it's better to rest immediately.
安かったら、これを買います。
yasukattara, kore wo kaimasu.
If it is cheap, I will buy this.
そんなに嫌だったら、やらなくてもいいですよ。
sonna ni iya dattara, yaranakute mo ii desu yo.
If you hate it that much, you don't have to do it.
4. Discovery (The "Surprise" Past)
デパートへ行ったら、休みでした。
depaato he ittara, yasumi deshita.
When I went to the department store, I found it was closed.
窓を開けたら、雪が降っていました。
mado wo aketara, yuki ga futte imashita.
When I opened the window, I saw it was snowing.
箱を開けたら、プレゼントが入っていました。
hako wo aketara, purezento ga haitte imashita.
When I opened the box, I discovered a present was inside.
5. Requests and Intentions
時間があったら、手伝ってください。
jikan ga attara, tetsudatte kudasai.
If you have time, please help me.
面白かったら、私にも貸してね。
omoshirokattara, watashi ni mo kashite ne.
If it's interesting, lend it to me too, okay?
東京に行ったら、カメラを買うつもりです。
toukyou ni ittara, kamera wo kau tsumori desu.
When I go to Tokyo, I intend to buy a camera.
Common Pitfalls
1. The Chronological Trap
❌ 日本に行ったら、チケットを買います。
✅ 日本に行くなら、チケットを買います。
Action A must happen before Action B in a 〜たら sentence. You cannot say "When I go to Japan, I'll buy a ticket" if you need that ticket to travel there in the first place. Use 〜なら for that situation.
2. Using it for Inevitable Facts
❌ 春になったら、花が咲きます。
✅ 春になると、花が咲きます。
While people will understand you, 〜たら sounds slightly conversational. For natural laws or things that happen automatically (like "If you push this button..."), the particle 〜と is much more natural.
3. Forgetting the "Datta"
❌ 暇なら、遊ぼう。
✅ 暇だったら、遊ぼう。
Students often forget that nouns and na-adjectives need the past form だった before the ら. While 〜なら is a valid grammar point, it has a different nuance than the 〜たら conditional.
Cultural Nuances
Japanese speakers often use 〜たら to avoid being too pushy. A phrase like 〜たらどうですか (How about if you did...?) is a polite way to suggest something without sounding like you are giving orders. It invites the other person to think about the possibility instead of telling them what to do.
You will also notice that Japanese people often trail off at the end of a sentence. If a friend asks if you're free to hike, you might just say 「雨が降ったら……」 (If it rains...). The listener knows you mean "If it rains, I won't go," but leaving it unsaid is more polite.
Related Grammar Points
- Sequence and Starting Points: Using てから (te kara) (Grammar N4)
- The Grammar of Appearance: Using ～そうだ (Grammar N4)
- The Causative Form: How to Say 'Make' or 'Let' (Grammar N4)
- なら (Nara): Contextual Conditional — If / If That's the Case (Grammar N4)
- Bakari (ばかり) — Just Did, Nothing But (Grammar N4)
- ように (You ni) — So That, In Order To (Grammar N4)
JLPT Tips
On the N4 exam, 〜たら appears constantly. A major clue to look for is the word もし (moshi) at the start of a sentence. While もし is optional, it acts as a "warning" that a conditional 〜たら is coming at the end of the clause.
Pay attention to the very end of the sentence. Does it end with a request like ください or a desire like 〜たい? If so, 〜たら is almost always the correct answer. The other conditionals (〜と and 〜ば) generally cannot be used with these subjective endings.
Lastly, remember the discovery rule for the reading section. If you see a past tense verb at the end of the sentence, and the sentence describes an observation, 〜たら is likely the link between the actions.