You Need to Ask When in Japanese
You’re planning a trip to Tokyo and need to confirm the meeting time with your guide. You’re watching an anime and the character mentions something happening “when the cherry blossoms fall.” You’re scheduling a video call with a language partner and must ask, “When are you free?”
In these moments, knowing how to express “when” in Japanese becomes crucial. It’s more than just translating a single word. Japanese offers multiple ways to ask about time, depending on whether you’re inquiring about a specific point, a general period, or a conditional moment.
This guide breaks down every essential “when” expression, from the basic interrogative to nuanced temporal clauses. You’ll learn the grammar, context, and pronunciation to communicate about time confidently.
The Foundation: The Basic Interrogative “When”
For direct questions about time, the word you need is “itsu.” Written in hiragana as いつ, this is your go-to question word equivalent to “when.” Its usage is straightforward and mirrors English in many simple queries.
You place “itsu” at the beginning of your question, similar to English word order. The particle “ka” at the end turns the sentence into a question, though in casual speech it is often dropped.
Formal and Common Questions with Itsu
Here are fundamental questions using “itsu” that you will use constantly.
When is it?
それはいつですか。
Sore wa itsu desu ka.
When will you come?
いつ来ますか。
Itsu kimasu ka.
When does the train arrive?
電車はいつ到着しますか。
Densha wa itsu touchaku shimasu ka.
When is your birthday?
誕生日はいつですか。
Tanjoubi wa itsu desu ka.
Notice the structure: Itsu + [Subject/Topic] + [Verb/Desu] + Ka. This pattern works for nearly any simple time inquiry.
The Nuance of Itsu
While “itsu” is versatile, it typically asks for a specific point in time or date. It implies an expectation of a concrete answer like “tomorrow,” “at 3 PM,” or “next week.” Using it for philosophical or vague time concepts can sound slightly odd.
For example, “When did you realize your dream?” (夢はいつ実現しましたか) works because one could answer with a life stage or year. It seeks a definable moment.
Beyond the Basic: Other Ways to Express “When”
Japanese doesn’t stop at “itsu.” The language has specific constructions for conditional time (“whenever”), past occasions (“when I was”), and relative time clauses. Mastering these unlocks natural, fluent expression.
Describing Simultaneous Actions: Toki
The word “toki” (時) means “time” or “occasion,” but it’s used to create “when” clauses that describe one action happening at the time of another. Think of it as “at the time that…” or “when…” in a descriptive sense.
Structure: [Verb Plain Form] + toki + [Main Clause].
When I go to Japan, I will eat sushi.
日本に行く時、寿司を食べます。
Nihon ni iku toki, sushi o tabemasu.
Note the verb before “toki” is in its plain, dictionary form (行く – iku, “to go”). This sentence describes a future plan.
When I was a child, I lived in Osaka.
子供の時、大阪に住んでいました。
Kodomo no toki, Oosaka ni sunde imashita.
Here, “toki” is preceded by a noun with the possessive particle “no” (子供の – kodomo no, “child’s”). This describes a past period.
The tense is implied by the main clause’s verb. “Toki” itself is neutral.
Expressing General or Conditional Time: Toki wa
Adding the topic particle “wa” creates “toki wa,” which can mean “as for when…” or set up a general temporal topic. It’s often used in explanations or when contrasting different times.
As for when it’s busy, it’s usually the evening.
忙しい時は、たいてい夜です。
Isogashii toki wa, taitei yoru desu.
This frames “busy times” as the topic of discussion.
The Conditional “When”: Tara and To
Sometimes “when” carries a conditional meaning—”when X happens, then Y will happen.” Japanese has specific grammatical forms for this, primarily the “tara” conditional and the “to” conditional.
The Tara Conditional (〜たら)
The “tara” form indicates a conditional sequence. It often translates to “when” in the sense of “once this happens, then that will follow.” It emphasizes the sequence of events.
Structure: [Verb in Tara Form] + [Main Clause].
When you arrive, please call me.
着いたら、電話してください。
Tsuitara, denwa shite kudasai.
The verb “tsuku” (to arrive) becomes “tsuitara” in its tara form. This implies “once the condition of you arriving is met, then please call.”
When I have money, I will buy a car.
お金があったら、車を買います。
Okane ga attara, kuruma o kaimasu.
Here, “aru” (to exist) becomes “attara.”
The To Conditional (〜と)
The “to” conditional expresses a natural, inevitable, or habitual consequence. “When X, always Y.” It’s used for scientific facts, machine operations, or personal habits.
Structure: [Verb Plain Form] + to + [Main Clause].
When I drink coffee, I wake up.
コーヒーを飲むと、目が覚めます。
Koohii o nomu to, me ga samemasu.
This suggests a reliable, almost automatic result.
When you press this button, the light turns on.
このボタンを押すと、電気がつきます。
Kono botan o osu to, denki ga tsukimasu.
This describes a mechanical, guaranteed outcome. Using “tara” here would also be correct, but “to” highlights the inevitability.
Asking About Specific Time Frames
Often, you’re not just asking “when,” but “about when” or “around what time.” Japanese has phrases for these nuanced inquiries.
About when will it be ready?
いつごろできますか。
Itsu goro dekimasu ka.
Adding “goro” (頃) after “itsu” softens the question, asking for an approximate time. It’s polite and useful when exact timing is uncertain.
From when to when?
いつからいつまでですか。
Itsu kara itsu made desu ka.
This essential phrase uses the particles “kara” (from) and “made” (until) to ask about a duration. Perfect for store hours, event lengths, or availability windows.
Practical Application in Conversation
Let’s apply these forms in common real-world scenarios. The key is choosing the right “when” for the context.
Scenario 1: Making Plans
You’re texting a friend to meet up.
You: When are you free this week?
今週、いつ暇ですか。
Konshuu, itsu hima desu ka.
(Basic “itsu” for a direct question about a specific time.)
Friend: I’m free on Friday.
金曜日は暇です。
Kinyoubi wa hima desu.
You: Great. When we meet, let’s go to that new cafe.
いいね。会う時、あの新しいカフェに行こう。
Ii ne. Au toki, ano atarashii kafe ni ikou.
(Using “toki” to describe the simultaneous action of meeting and going.)
Scenario 2: Giving Instructions
You’re explaining a process to a colleague.
“When the report is finished, please email it to the manager. When you send it, use this subject line.”
レポートが完成したら、マネージャーにメールしてください。送る時、この件名を使ってください。
Repooto ga kansei shitara, maneekaa ni meeru shite kudasai. Okuru toki, kono kenmei o tsukatte kudasai.
Here, “shitara” is used for the first conditional “when” (once the finish condition is met, do the action). “Okuru toki” is used for the second “when,” describing the action taken at the time of sending.
Common Mistakes and How to Avoid Them
Even intermediate learners mix up these forms. Here are pitfalls to watch for.
Mistake 1: Using “itsu” for descriptive clauses.
Wrong: いつ日本に行きます、寿司を食べます。
Correct: 日本に行く時、寿司を食べます。
“Itsu” starts a question. You cannot use it to mean “at the time that.” You must use “toki,” “tara,” or “to.”
Mistake 2: Confusing “toki” with “tara” for conditionals.
“Toki” describes a simple time overlap. “Tara” emphasizes a condition leading to a result.
When I opened the window (and at that moment), it was cold.
窓を開けた時、寒かった。
Mado o aketa toki, samukatta.
(Describing the state at the moment of opening.)
When I opened the window, (then) a bird flew in.
窓を開けたら、鳥が入ってきた。
Mado o aketara, tori ga haitte kita.
(The opening directly preceded and allowed the new event.)
Mistake 3: Overusing the “to” conditional.
Remember, “to” implies a strong, habitual, or inevitable link. Don’t use it for one-off, uncertain future plans.
Weak: When I go to Paris (someday), I’ll see the Eiffel Tower.
Better with Tara: パリに行ったら、エッフェル塔を見ます。
Pari ni ittara, Efferu Tou o mimasu.
Using “to” here would sound like every single time you go to Paris, without fail, you see it, which is unnatural for a future plan.
Mastering Pronunciation and Politeness
Correct pronunciation ensures you’re understood. “Itsu” is pronounced “ee-tsoo,” with a short “i” and a clear “ts” sound. “Toki” is “toh-kee.”
Particle “wa” is pronounced “wa,” but the topic particle is written as “ha” (は) and pronounced “wa.” So “toki wa” is written 時は but said “tokee wa.”
For politeness, adjust the verb endings in your main clauses, not necessarily the “when” clause itself. The conditional and “toki” structures often use plain form verbs before them, but the final verb dictates the politeness level.
Casual: When I get home, I’ll eat.
家に帰ったら、食べる。
Ie ni kaettara, taberu.
Polite: When I get home, I will eat.
家に帰ったら、食べます。
Ie ni kaettara, tabemasu.
The “tara” clause (帰ったら) remains the same. Only the final verb changes from plain “taberu” to polite “tabemasu.”
Your Action Plan for Fluency
Start by drilling the basic “itsu” questions. Write down five things you want to ask about timing and formulate the questions. Then, move to combining sentences with “toki.” Take two simple sentences and link them.
Practice the conditionals by thinking of cause-and-effect scenarios. “When it rains, I use an umbrella.” Build the sentence with both “tara” and “to” to feel the difference in nuance.
Listen for these patterns in Japanese media. Anime, dramas, and podcasts are full of “itsu,” “toki,” and “tara.” Shadow the sentences to improve muscle memory.
Finally, use them. In your next language exchange, consciously ask a question with “itsu goro” or describe your day using “toki.” Real communication cements the knowledge far better than isolated study.
Expressing “when” is a gateway to detailed plans, stories, and instructions. By understanding these core tools—itsu for questions, toki for description, tara and to for conditions—you gain precise control over discussing time. Move beyond simple translation and start thinking in the natural patterns of Japanese time expression.
