English says "if" for nearly everything. Japanese has four common conditional forms, と, ば, たら, and なら, and they are not interchangeable. The JLPT loves testing this distinction at N4 and N3.
The good news is that you can get most answers right with a few clear rules. Let's compare them.
Quick comparison
| Form | Rough meaning | Best for |
|---|---|---|
| ～と | whenever / when X, always Y | natural results, habits, discoveries |
| ～ば | if X (condition), then Y | general conditions, proverbs, requirements |
| ～たら | if / when X happens | specific situations, the most flexible |
| ～なら | if (as you say) / in that case | responding to given information |
～と: natural consequences
と connects a condition to a result that always or automatically follows.
- 春になると、桜が咲きます。— When spring comes, the cherry blossoms bloom.
- ボタンを押すと、ドアが開きます。— If you press the button, the door opens.
- 右に曲がると、駅があります。— If you turn right, there's a station.
Limit: The second half cannot be a request, command, invitation, or intention. You cannot say ✕ 雨が降ると、行かないでください.
How to form it: plain form of the verb or adjective + と.
～ば: general conditions
ば expresses a condition for something to be true. It often implies "if only X, then Y."
- 安ければ、買います。— If it's cheap, I'll buy it.
- 勉強すれば、合格できます。— If you study, you can pass.
- 急がなければ、遅れますよ。— If you don't hurry, you'll be late.
It is common in proverbs and in expressions like ～ばよかった (I should have...).
Forming it:
- Ichidan verbs: drop る, add れば (食べる → 食べれば).
- Godan verbs: change the final u-sound to the e-sound, add ば (書く → 書けば, 飲む → 飲めば).
- i-adjectives: drop い, add ければ (安い → 安ければ).
- Nouns and na-adjectives: であれば or なら.
If you are unsure how verb groups work, see ichidan vs godan verbs.
～たら: the flexible one
たら is formed from the past (た) form + ら. It means "if" or "when" for a specific situation, and it can be followed by requests, intentions, and commands.
- 雨が降ったら、行きません。— If it rains, I won't go.
- 駅に着いたら、電話してください。— When you arrive at the station, please call me.
- 宿題が終わったら、遊んでもいいです。— After you finish your homework, you may play.
Because it handles so many cases, たら is the safest choice for learners. If you are unsure which to use, たら is usually correct, with one exception: it is not natural for general truths or scientific facts, where と fits better.
～なら: given the topic
なら picks up information the other person has just mentioned or that is clearly established, and responds to it.
- A: 京都に行きます。— I'm going to Kyoto. B: 京都に行くなら、お寺を見るといいですよ。— If you're going to Kyoto, you should see the temples.
- 日本語を習うなら、この教科書がいいです。— If you're learning Japanese, this textbook is good.
Key idea: なら follows something already known in the conversation. You are not describing something that will happen; you are responding.
Decision shortcuts
- Is the result automatic or a natural law? → と
- Is the speaker making a request, suggestion, or stating a will in the result? → たら or なら (not と)
- Is the other person's statement being picked up? → なら
- A general condition or proverb-like statement? → ば
- When in doubt → たら
Common mistakes
- Using と before a request: ✕ 時間があると、来てください. Use たら.
- Using ば with a result that is a request or past action. Generally ば prefers states or general results.
- Confusing なら with たら. なら looks backward to given information; たら describes what happens when a situation occurs.
How the JLPT tests this
Typical question: "お金（ ）、旅行に行きたい。" with options like あると / あれば / あったら / あるなら. You need to see the sentence meaning and the restrictions to pick the best one. Practicing with explanations is essential, because "all four are grammatical" in isolation is common; context decides.
When you miss one, record it in a mistake log with the reason (e.g. "と cannot be followed by a request"). That reasoning is what sticks.
Next steps
Conditionals fit into the bigger N4 picture described in the JLPT N4 study plan. For a full overview of levels and sections, see the JLPT preparation guide. JLPT Ready's Learn section gives plain-language explanations for each grammar point and links to practice questions, with an AI explanation for every question. You can start free with N5 and work your way up.