Temporal clauses: とき, 前に, あとで, てから, ながら, うちに
A2 時の節「〜とき・〜前に・〜あとで・〜てから・〜ながら・〜うちに」 23 / 69
In short
Japanese says “when / before / after / while” by putting a clause in front of a time word: [clause] + とき／前に／あとで. The only thing you have to get right is which verb form attaches, and it is fixed by the connector, not by the tense of the sentence: 前に always takes the dictionary form, あとで always takes the た-form, ながら takes the ます-stem. Everything else follows.
The rule
A temporal clause is not a new structure. It is the noun-modifying clause from lesson 18 put in front of a time noun, and the whole block then sits at the front of the sentence, usually with a 、after it. The main clause comes last and carries the politeness:
[ Clause, plain form ] + とき／前に／あとで、 [ main clause ]
Step 1 - Put the subordinate verb in the plain form. です／ます lives on the final predicate only. ×食べますとき is wrong however polite the sentence is; the correct shape is 食べるとき…食べます。 This is the single most visible error in the whole topic, and it applies to every connector below.
Step 2 - Attach the form the connector demands.
- V-dictionary + 前に (mae ni, before). Nouns take の: 食事の前に (shokuji no mae ni, before the meal).
- V-た + あとで (ato de, after). Nouns take の: 食事のあとで.
- V-て + から (te kara, after / once).
- V-ます-stem + ながら (nagara, while).
- plain form + とき (toki, when). Nouns take の, な-adjectives take な.
- plain non-past or ない + うちに (uchi ni, while it still is). Nouns take の: 休みのうちに.
- V-dictionary + たびに (tabi ni, every time). Nouns take の: 会議のたびに.
Step 3 - Ignore the main clause tense when choosing 前に and あとで. This is where English misleads you. English says before I go but before I went; Japanese says 行く前に both times. 前に is locked to the dictionary form and あとで is locked to た, no matter whether the sentence as a whole is past or future:
- 寝る前に、歯を磨きます。 - Before I go to bed, I brush my teeth.
- 寝る前に、歯を磨きました。 - Before I went to bed, I brushed my teeth.
Think of the form as describing the order of the two events, not the position of either one relative to now. In 前に the clause verb has not happened yet at that point, so it is non-past; in あとで it has finished, so it is た.
Step 4 - With とき, the tense is real and it means something. Unlike 前に and あとで, とき accepts both forms, and the choice changes the meaning. The tense inside とき is judged against the main event, not against now - exactly the relative-tense rule from lesson 18. The classic pair:
- 日本へ行くとき、辞書を買いました。 (Nihon e iku toki…) - the buying happened when the going was not yet complete: before departure or on the way. You bought it at home or at the airport.
- 日本へ行ったとき、辞書を買いました。 (Nihon e itta toki…) - the going was already complete: you had arrived. You bought it in Japan.
So 行くとき = when going / before arriving, 行ったとき = when I got there / after arriving. Ask yourself: at the moment of the main event, had the とき verb finished or not?
Step 5 - ながら has two hard conditions. Both clauses must have the same subject, and the ながら verb must be durative - something that lasts (聞く, 歩く, 食べる, 見る), not an instant change (死ぬ, 着く). The main clause is the primary action and ながら is the accompanying one: 音楽を聞きながら勉強します means I study, with music on - the point of the sentence is the studying. Swap them and you have changed what you said. If the two subjects differ, ながら is impossible; use 間に instead (below).
Step 6 - てから vs あとで. Both put B after A, but てから adds that A is a required precondition: B only becomes possible once A is done. 仕事が終わってから帰ります means I go home once work is finished - finishing is the gate. 仕事が終わったあとで帰ります is a neutral report of the order. てから also chains naturally into a sequence of steps in a procedure, which is why recipes and instructions are full of it.
Step 7 - 間 vs 間に. 間 (aida) and 間に (aida ni) both mean during, and the に decides the shape of the main clause. Bare 間 = the main action lasts the whole span: 寝ている間、雨が降っていました (it rained the whole time I was asleep). 間に = the main action happens at one point inside the span: 寝ている間に、雨が降りました (it rained while I was asleep - it started and stopped in there). Rule of thumb: durative main clause -> 間, punctual main clause -> 間に.
Step 8 - うちに: before the state changes. うちに means while a state still holds, before it changes - and that “before it changes” is the whole point; it is not a neutral while. It attaches to a plain non-past form: 若いうちに (wakai uchi ni, while you are still young), 明るいうちに (akarui uchi ni, while it is still light); to a noun with の: 休みのうちに (yasumi no uchi ni, while the holiday lasts), 今のうちに (ima no uchi ni, while you still can); and very commonly to a ない form: 忘れないうちに (wasurenai uchi ni, before I forget), 雨が降らないうちに (ame ga furanai uchi ni, before it starts raining). Note that ない + うちに is translated by English before, not while - the Japanese literally says “while it is not yet raining”. After a clause うちに is normally graded N3; after a noun it is everyday speech, and 今のうちに is worth using now. Either way, let 間に carry your neutral while.
Forms & patterns
The attachment table - the spine of this lesson. The verb form is fixed by the connector. Memorise this column, not the translations.
| Connector | Attaches to | Verb example | Noun / adjective | Meaning |
|---|---|---|---|---|
| とき | plain form, any tense | 行くとき iku toki ／ 行ったとき itta toki | 学生のとき, ひまなとき | when |
| 前に | dictionary form only | 行く前に iku mae ni | 食事の前に shokuji no mae ni | before |
| あとで | た-form only | 行ったあとで itta ato de | 食事のあとで shokuji no ato de | after |
| てから | て-form | 行ってから itte kara | - | after / once |
| ながら | ます-stem | 行きながら ikinagara | - | while (same subject) |
| うちに | plain non-past or ない | 忘れないうちに wasurenai uchi ni | 若いうちに wakai uchi ni, 休みのうちに yasumi no uchi ni | while it still is |
| たびに | dictionary form | 会うたびに au tabi ni | 会議のたびに kaigi no tabi ni | every time |
とき by word class. The non-past row of な-adjectives and nouns is where learners slip: な and の, never だ.
| Class | Form before とき | Romaji | Meaning |
|---|---|---|---|
| Verb, non-past 行く | 行くとき | iku toki | when going / before arriving |
| Verb, past 行った | 行ったとき | itta toki | when I got there / after arriving |
| Verb, negative 行かない | 行かないとき | ikanai toki | when I don’t go |
| い-adjective 若い | 若いとき | wakai toki | when young |
| な-adjective ひま | ひまなとき | hima na toki | when free |
| Noun 学生 | 学生のとき | gakusei no toki | when I was a student |
The ます-stem for ながら, across the three verb classes:
| Class | Dictionary | ます-form | + ながら |
|---|---|---|---|
| 五段 (godan) 聞く | 聞く kiku | 聞きます | 聞きながら kikinagara |
| 一段 (ichidan) 食べる | 食べる taberu | 食べます | 食べながら tabenagara |
| Irregular する | する suru | します | しながら shinagara |
| Irregular 来る | 来る kuru | 来ます | 来ながら kinagara (rare - see note) |
Note on 来ながら. The stem is formed regularly (来ます -> 来 ki), but 来る is a change-of-location verb, not a durative one, so a bare 来ながら is rare in the “while doing” sense - it falls foul of the same restriction as 着く in Step 5, and in real text you mostly meet it inside compounds (〜て来ながら). Take the row as stem practice; build actual ながら sentences from durative verbs like 聞く, 歩く, 食べる.
Choosing between the overlapping ones:
| Pattern | Japanese | Romaji | What it signals |
|---|---|---|---|
| てから | 仕事が終わってから帰ります。 | shigoto ga owatte kara kaerimasu | B only once A is done - A is the gate |
| たあとで | 仕事が終わったあとで帰ります。 | shigoto ga owatta ato de kaerimasu | plain order in time, no condition implied |
| 間 | 寝ている間、雨が降っていました。 | nete iru aida, ame ga futte imashita | main clause fills the whole span |
| 間に | 寝ている間に、雨が降りました。 | nete iru aida ni, ame ga furimashita | main clause is a point inside the span |
| うちに | 明るいうちに帰ります。 | akarui uchi ni kaerimasu | do it before the state ends |
Examples
- 日本へ行くとき、空港で辞書を買いました。 (Nihon e iku toki, kūkō de jisho o kaimashita.) - When I went to Japan, I bought a dictionary at the airport (before arriving).
- 日本へ行ったとき、この写真を撮りました。 (Nihon e itta toki, kono shashin o torimashita.) - When I went to Japan, I took this photo (after arriving).
- 学生のとき、京都に住んでいました。 (Gakusei no toki, Kyōto ni sunde imashita.) - When I was a student, I lived in Kyoto.
- 寝る前に、歯を磨きます。 (Neru mae ni, ha o migakimasu.) - Before going to bed, I brush my teeth.
- 食事の前に、手を洗ってください。 (Shokuji no mae ni, te o aratte kudasai.) - Please wash your hands before the meal.
- 宿題をしたあとで、テレビを見ます。 (Shukudai o shita ato de, terebi o mimasu.) - After doing my homework, I watch television.
- 仕事が終わってから、買い物に行きます。 (Shigoto ga owatte kara, kaimono ni ikimasu.) - Once work is over, I go shopping.
- 音楽を聞きながら、勉強します。 (Ongaku o kikinagara, benkyō shimasu.) - I study while listening to music.
- 明るいうちに、帰りましょう。 (Akarui uchi ni, kaerimashō.) - Let’s go home while it is still light.
- 忘れないうちに、メモします。 (Wasurenai uchi ni, memo shimasu.) - I’ll write it down before I forget.
Common mistakes
- 日本へ行きますとき (Nihon e ikimasu toki) -> 日本へ行くとき (Nihon e iku toki) - the verb inside a temporal clause is plain, even when the sentence ends in ます. Politeness is marked once, on the final predicate.
- 寝た前に、歯を磨きました。 (Neta mae ni, ha o migakimashita.) -> 寝る前に、歯を磨きました。 (Neru mae ni, ha o migakimashita.) - 前に takes the dictionary form always. The past tense of the sentence lives on 磨きました, not on the clause.
- ご飯を食べるあとで、薬を飲みます。 (Gohan o taberu ato de, kusuri o nomimasu.) -> ご飯を食べたあとで、薬を飲みます。 (Gohan o tabeta ato de, kusuri o nomimasu.) - あとで takes た always, even about the future. The eating is finished at that point in the story.
- 音楽を聞くながら、勉強します。 (Ongaku o kiku nagara, benkyō shimasu.) -> 音楽を聞きながら、勉強します。 (Ongaku o kikinagara, benkyō shimasu.) - ながら attaches to the ます-stem (聞き-), not the dictionary form.
- 学生ときアルバイトをしました。 (Gakusei toki arubaito o shimashita.) -> 学生のときアルバイトをしました。 (Gakusei no toki arubaito o shimashita.) - とき is a noun, so a noun links to it with の and a な-adjective with な: ひまなとき, not ×ひまのとき or ×ひまだとき.
Tips
- 前に and あとで have no tense of their own - they encode order. Lock in the pair “前に = 辞書形 (dictionary), あとで = た形” and never look at the main verb again. English before I went is a trap that makes learners write ×行った前に; Japanese has already said “before”, so the clause verb stays unfinished.
- For とき, ask one question: at the moment of the main event, had that verb finished? Not finished -> non-past (日本へ行くとき, still travelling). Finished -> た (日本へ行ったとき, already there). The same test explains 家を出るとき鍵をかけます (lock up as you leave) vs 家を出たとき雨が降っていました (it was raining once I was outside).
- English while splits three ways in Japanese. Same subject, two simultaneous actions -> ながら. Different subjects, or one action inside another’s span -> 間に. “While it still is, before it changes” -> うちに. ×子どもが寝ながら掃除しました is wrong because the subjects differ: say 子どもが寝ている間に掃除しました.
- Spelling note. とき and うち are normally written in kana in this grammatical use, though you will meet 時 and 内 in print; 前 and 後 are written in kanji, so 〜たあとで often appears as 〜た後で. All are the same words - do not treat the kanji version as a different pattern.