“tara vs ba”: Distinguishing Conditional Expressions [JLPT N3]

Content by NTJ Kuma · Nihongo to Japan editorial team · Updated July 27, 2026

「雨が降ったら行かない」vs「雨が降れば行かない」 — what's the difference between たら and ば?

Why 「家に帰ったら電話して」 but not 「帰れば電話して」? — the division of labor between たら and ば

「家に帰ったら、電話して」 (call me after you get home) — swap it to 「帰れば電話して」 and it sounds off. 「たら」 and 「ば」 both render as “if ～ then,” but たら is more general (takes commands, will, time sequence, chance discovery), ば leans toward general conditions, truths, counterfactuals. This guide uses a practical division-of-labor table to sort out when to use each of these two N3 conditionals, cross-comparing 「と／なら」.

Core: たら is general (incl. time sequence, chance discovery); ば leans general condition, truth, counterfactual

Both mark conditions, but with different scope:

• たら = more general, colloquial: can express “B after A completes (time sequence),” “chance discovery (past),” “hypothesis,” “counterfactual,” and can take commands, requests, will afterward.
• ば = leans ‘general condition, truth, counterfactual': universal regularities, maxims, hypotheses, but the second clause in principle takes no command/will (except when the first clause is a state).

The most practical dividing line: when the second clause is a command, request, or will (〜して／〜しよう／〜たい), 「たら」 is safest (帰ったら電話して = call after you get back). 「ば」 is mostly for general conditions and truths without a following action-command (春になれば桜が咲く = when spring comes, cherries bloom).

Attachment & uses compared

Examples in use

• 家に帰ったら、手を洗いましょう。(After getting home, let's wash our hands.) — time sequence ＋ will (たら only)
• ボタンを押せば、ドアが開きます。(Press the button and the door opens.) — general condition (ば typical)
• もっと早く出発すれば、間に合ったのに。(If only we'd left earlier, we'd have made it.) — counterfactual (ば)
• 窓を開けたら、猫が入ってきた。(When I opened the window, a cat came in.) — chance discovery (たら only)
• 安ければ、買います。(If it's cheap, I'll buy it.) — general condition (ば)

⚠️ Easy traps to avoid

① When the second clause is a command/request/will, use 「たら」 not 「ば」. The most practical rule. For “after (doing A), please/I'll do B” — use たら: 駅に着いたら、電話して (call after you reach the station, ○); 空いたら、座ろう (if a seat opens up, let's sit, ○). 「ば」 in principle takes no command/will afterward (×駅に着けば電話して is unnatural). Only when the first clause is a stative verb/adjective can ば barely take a will (時間があれば行く). When unsure, if 「〜して／〜しよう／〜たい」 follows, pick たら.

② ‘Chance discovery, a past one-off event' can only use 「たら」. For “did A, and (unexpectedly) found B” (past, one-off), only たら: ドアを開けたら、誰もいなかった (I opened the door and no one was there, ○); 家に帰ったら、荷物が届いていた (I got home and the parcel had arrived, ○). This “did …, then discovered …” use can't use ば (×開ければ誰もいなかった).

③ 「ば」 excels at general conditions, truths, maxims, counterfactuals. For universal regularities, truths, ば is most typical: 春になれば暖かくなる (when spring comes, it warms up); 塵も積もれば山となる (many a little makes a mickle, a proverb); for counterfactual regret ば is common too: 勉強すればよかった (if only I'd studied). In these “no concrete following action, stating a general principle or hypothesis” settings, ば is more written and typical than たら.

🔄 Compare: たら／ば／と／なら

💡 Learning tip

「たら」 and 「ば」 both render as “if ～ then,” but with a clear division: たら is most general, colloquial (post-completion condition, time sequence, chance discovery, hypothesis, counterfactual all work, and it takes commands/requests/will afterward); ば leans general condition, truth, maxim, counterfactual (the second clause in principle takes no command/will). Three practical tests: ① 「〜して／〜しよう／〜たい」 (command/will) follows → use たら (帰ったら電話して ○; 帰れば電話して ✗); ② past ‘did …, then (unexpectedly) found …' chance discovery → たら only (開けたら猫がいた); ③ universal regularity, truth, counterfactual regret → ば most typical (押せば開く, 勉強すればよかった). Add 「と」 (inevitable linkage, also no command) and 「なら」 (advice from a premise), and the four conditionals fall into place. When lost, remember: to tell someone to do something or state will, たら is never wrong.

❓ Quick FAQ

Q: Why is 「家に帰ったら電話して」 right but 「家に帰れば電話して」 odd?

Because 「ば」's second clause in principle takes no command, request, or will, and 「電話して」 is exactly a request. This sentence means “after (completing) getting home, (please) call” — a “B after A completes” time sequence ＋ request, which needs 「たら」: 家に帰ったら、電話して (○). 「たら」 inherently expresses “B only after A is realized/done,” and freely takes commands, requests, will (〜して／〜しよう／〜なさい/〜たい). But 「ば」 leans ‘a general condition, a hypothesis holding,' its second clause customarily a statement or judgment, not a concrete action-command: so 「帰れば電話して」 sounds like “(as long as) getting home (holds as a condition), call,” treating “get home” as a trigger rather than a completed prior action, and with a request following, it's unnatural. (Only when the first clause is a state can ば take will: 時間があれば行きます = if I have time, I'll go, ○.) Rule: when the second clause tells someone to “do …” (command/request/will), almost always use たら, not ば.

Q: Then when can 「たら」 and 「ば」 be swapped?

When expressing a ‘general condition, hypothesis' with no command/will following, they're often interchangeable, with a slight feel difference. E.g., この薬を飲めば治る／飲んだら治る (take this medicine and you'll recover — both work; ば more like stating a general principle, たら more colloquial, more like a specific instance). 安ければ買う／安かったら買う (if cheap, I'll buy — both fine). Counterfactual regret works with both: 勉強すればよかった／勉強したらよかった (if only I'd studied). But memorize the non-interchangeable cases: ① a following command/request/will → たら only (帰ったら電話して); ② past chance discovery → たら only (開けたら猫がいた); ③ pure truths, maxims, abstract regularities → ば more typical, more written (塵も積もれば山となる). So the big principle: for a general condition with no following action-command, たら/ば are mostly swappable; once a command/will follows, or you're describing a past chance discovery, it must be 「たら」. (「と」, marking inevitable linkage, is also often compared, but 「と」's second clause likewise takes no command/will — see the related 〈たら/ば/と/なら〉 guides.)

🖊️ Practice Quiz

Q1. 「家に帰っ___、電話してください。」(temporal sequence + request) Which is correct?

(A) れば　(B) たら　(C) たり　(D) て

Q2. 「毎日練習___、上手くなります。」(a general condition) Which is correct?

(A) したら　(B) すれば　(C) したり　(D) して

Q3. 「もっと早く来___よかった。」(counterfactual, regret) Which is correct?

(A) たら　(B) れば　(C) て　(D) both A and B (ばよかった is more natural)

Q4. 「ドアを開け___、猫がいた。」(an accidental discovery) Which is correct?

(A) れば　(B) たら　(C) ると　(D) both B and C

Q5. What's the most important difference between ば and たら?

(A) only the connection differs

(B) ば is general/counterfactual condition; たら is one-time/temporal-sequence, and its latter can take a request/command

(C) たら is written, ば is spoken

(D) identical and interchangeable

Answer Key

1. (B) たら ── 帰ったら電話してください = temporal sequence + a request in the latter; a request/command latter uses たら. (帰れば電話して is unnatural.)

2. (B) すれば ── a general condition: 練習すれば上手くなる.

3. (D) both A and B ── 来ればよかった/来たらよかった (regret); ばよかった is more natural.

4. (D) both B and C ── 開けたら/開けると、猫がいた (an accidental discovery).

5. (B) ── ば is general/counterfactual; たら is one-time/temporal-sequence, and its latter can take a request/command.