Japanese Grammar

Conditionals: ใ€œใŸใ‚‰ (~tara)

The ~tara form is the most versatile conditional in Japanese. Depending on the context, it means 'If (A happens), then (B)' or 'When (A happens in the future), then (B)'.

If and When

Unlike English which has different words for 'If' (uncertain) and 'When' (certain to happen), Japanese often uses the exact same grammar: ใ€œใŸใ‚‰.

If the condition is a hypothetical (e.g., If I have money...), ~tara means 'If'.

If the condition is definitely going to happen in the future (e.g., When I arrive at the station...), ~tara means 'When'.

Because of this, ~tara literally translates to 'Upon the completion of A, B will happen.'

How to make the ~tara form

Verbs (Use the Ta-form)
Rule
โ†’Ta-form + ใ‚‰ (ra)
Just add 'ra' to the past tense
้ฃŸในใ‚‹ (taberu)
โ†’้ฃŸในใŸใ‚‰ (tabetara)
If/When I eat
่กŒใ (iku)
โ†’่กŒใฃใŸใ‚‰ (ittara)
If/When I go
I-Adjectives
Rule
โ†’Change 'i' to 'kattara'
Past tense (katta) + ra
ๅฎ‰ใ„ (yasui)
โ†’ๅฎ‰ใ‹ใฃใŸใ‚‰ (yasukattara)
If it is cheap
ใ„ใ„ (ii - good)
โ†’ใ‚ˆใ‹ใฃใŸใ‚‰ (yokattara)
If it is good / If you like
Nouns and Na-Adjectives
Rule
โ†’Add ใ ใฃใŸใ‚‰ (dattara)
Past tense of da (datta) + ra
้›จ (ame - rain)
โ†’้›จใ ใฃใŸใ‚‰ (ame dattara)
If it rains
ๆš‡ (hima - free time)
โ†’ๆš‡ใ ใฃใŸใ‚‰ (hima dattara)
If you are free
Negative (If not...)
Rule
โ†’Nakatta + ra
Past negative + ra
่กŒใ‹ใชใ„ (ikanai)
โ†’่กŒใ‹ใชใ‹ใฃใŸใ‚‰ (ikanakattara)
If I don't go

Example Sentences

ใŠ้‡‘ใŒใ‚ใฃใŸใ‚‰ใ€่ปŠใ‚’่ฒทใ„ใพใ™ใ€‚
Okane ga attara, kuruma o kaimasu.
If I had money, I would buy a car. (Hypothetical = If)
ๆ—ฅๆœฌใซ็€ใ„ใŸใ‚‰ใ€้›ป่ฉฑใ—ใพใ™ใ€‚
Nihon ni tsuitara, denwa shimasu.
When I arrive in Japan, I will call you. (Certain future = When)
้›จใ ใฃใŸใ‚‰ใ€่กŒใใพใ›ใ‚“ใ€‚
Ame dattara, ikimasen.
If it rains, I won't go. (Noun + dattara)

Teacher's Advice

The nuance of completion

Why is ~tara based on the PAST tense (ta-form)? Because in the Japanese mind, the second action cannot happen until the first action is COMPLETELY FINISHED in the timeline. 'Arrive-ta-ra' -> Upon the completion of arriving, I will call.

JLPT Exam Patterns

  • โ€ขConjugating negative conditions correctly: ~nakattara (N4)
  • โ€ขUsing 'Moshi' (ใ‚‚ใ—) at the beginning of the sentence to emphasize that it's a hypothetical 'If' (N4)
  • โ€ขUnderstanding the difference between ~tara (after A happens) and ~te iru aida ni (while A is happening) (N4)

ใ€œใŸใ‚‰ as a Polite Suggestion

Outside of straightforward conditionals, ใ€œใŸใ‚‰ has a very common conversational use that textbooks often skip: gently suggesting something, without the bluntness of a direct command. ๆ—ฉใๅฏใŸใ‚‰๏ผŸ doesn't literally ask 'if you sleep early, then...'. It means something closer to 'why don't you go to sleep early?' The conditional structure softens what would otherwise sound like an order.

This pattern is everywhere in casual speech: ็—…้™ขใซ่กŒใฃใŸใ‚‰๏ผŸ ('maybe go to the hospital?'), ่žใ„ใฆใฟใŸใ‚‰๏ผŸ ('why not just ask?'). Recognizing this use matters for listening comprehension, since if you only know ใ€œใŸใ‚‰ as 'if/when,' these suggestions can sound like unfinished sentences rather than complete advice.

Frequently Asked Questions

What is the difference between ใ€œใŸใ‚‰ and ใ‚‚ใ—?

ใ‚‚ใ— is not a separate grammar point. It's an optional word that goes at the front of a ใ€œใŸใ‚‰ sentence to flag that what follows is hypothetical: ใ‚‚ใ—้›จใŒ้™ใฃใŸใ‚‰ใ€่กŒใใพใ›ใ‚“ (If it happens to rain, I won't go). You can drop ใ‚‚ใ— and the sentence still works (้›จใŒ้™ใฃใŸใ‚‰ใ€่กŒใใพใ›ใ‚“), but adding it makes the 'if' reading unambiguous, which is useful when the same sentence could otherwise be read as 'when.'

Why is the ~tara form built from the past tense (ta-form)?

Because in Japanese, the second event is only relevant once the first one is fully finished: ้ฃŸในใŸใ‚‰ (tabetara) literally frames it as 'upon the completion of eating.' This is different from English 'if/when I eat,' which doesn't grammatically mark completion. It's a small structural detail, but it explains why every ~tara form starts from a past-tense base rather than the dictionary form.

Related Grammar

Master Conditionals

Practice converting verbs and adjectives into the ~tara form.

Japanese ใ€œใŸใ‚‰ (~tara) Form: 'If' and 'When' | Nihongo Pass