English has one word for “if.” Japanese has four. Each one implies different things about probability, timing, and speaker control. This is one of the most-asked grammar questions — here’s the definitive answer.
Quick Comparison Chart
| Conditional | Best For | Nuance |
|---|---|---|
| たら | Most versatile “if/when” | Sequence: A happens, then B. Works everywhere. |
| ば | Hypothetical conditions | If A is true, B follows. General/habitual. |
| と | Automatic/natural results | Whenever A happens, B always follows. |
| なら | Topic-based “if” | If we’re talking about A, then B. Advice/opinion. |
1. たら — The Safe Choice
Formation: Past tense + ら
食べた + ら → 食べたら (if/when you eat)
安かった + ら → 安かったら (if it’s cheap)
Use for: Almost any “if” situation. When in doubt, use たら.
明日雨が降ったら、家にいます。(If it rains tomorrow, I’ll stay home.)
駅に着いたら、電話してね。(When you arrive at the station, call me.)
2. ば — Hypothetical Conditions
Formation: Change final う sound to え + ば
行く → 行けば · 食べる → 食べれば · 高い → 高ければ
Use for: Hypothetical or general conditions. Often for advice.
勉強すれば、合格できる。(If you study, you can pass.)
安ければ、買います。(If it’s cheap, I’ll buy it.)
3. と — Automatic Results
Formation: Dictionary form + と
行く + と · 食べる + と
Use for: Cause-effect that always happens. Facts, instructions, natural laws.
ボタンを押すと、ドアが開く。(Press the button and the door opens.)
春になると、桜が咲く。(When spring comes, cherry blossoms bloom.)
Cannot use for: Requests, invitations, or volitional actions in B.
4. なら — Topic-Based If
Formation: Plain form + なら
行く + なら · 学生 + なら
Use for: Giving advice or opinion based on what someone told you.
日本に行くなら、京都がおすすめです。(If you’re going to Japan, I recommend Kyoto.)
安いなら、買おう。(If it’s cheap, let’s buy it.)
Decision Flowchart
- Is it a natural/automatic result? → Use と
- Are you giving advice based on something stated? → Use なら
- Is it a hypothetical/general condition? → Use ば
- Not sure? → Use たら (it works almost everywhere)
Mastering Conditionals Takes Practice
Reading grammar explanations helps, but real mastery comes from seeing these patterns in context hundreds of times. Kanjijo’s SRS flashcards include example sentences using all four conditionals naturally.
SRS flashcards with real example sentences. Conditionals become natural through repetition. Free on iOS.