Meaning & Usage
The suffix た (ta) is the plain-form past tense marker in Japanese. It attaches to verbs, い-adjectives, and nominal predicates (な-adjectives and nouns) to express that an action was completed in the past or that a state existed in the past. Along with its negative counterpart なかった (nakatta), た forms the backbone of past-tense expression in everyday Japanese.
English marks the past tense by changing verbs internally — "eat" becomes "ate," "go" becomes "went," "is" becomes "was." Japanese works differently: it adds or modifies an ending to the word's base form. That ending is た (ta) or, after certain voiced sounds, だ (da). The result is an unambiguous past-tense marker sitting at the very end of the predicate.
Register matters early. The level of formality shifts which form you reach for:
- Plain/casual form (た): Used in conversation among friends, family members, and close acquaintances. Also used universally in subordinate clauses regardless of the surrounding register, and in most written Japanese.
- Polite form (ました): Used with strangers, superiors, or in formal and professional environments. This is formed from the polite stem ます plus the past ending た — in other words, ました is simply the polite version of た.
A useful mental model: think of た as a time stamp placed at the very end of a sentence. In Japanese, tense is always marked at the end of the predicate — you hear all the content of a sentence before learning when it occurred. For example, 昨日映画を見た means "Yesterday, I watched a movie." The time word (昨日), the object (映画), and the action (見) all come before the final た tells you when it happened. This structure is foreign to English speakers, and getting comfortable with it is central to fluency.
The plain past form た is also the standard in written Japanese: novels, newspaper articles, manga narration, and formal documents all default to it. Even when polite ました appears in dialogue, the surrounding narration typically uses plain た. This means た matters as much for reading as for speaking.
た also feeds into patterns you will meet as you progress: past experience (たことがある), conditionals (たら), listing actions (たり～たりする), and noun-modifying relative clauses. Every one depends on a correctly formed た — which makes drilling this form early one of the better investments at the N5 level.
Structure & Formation
How to form た depends entirely on the type of word being conjugated. Japanese verbs are divided into three groups, and adjectives and nouns follow their own distinct patterns. Each group has its own fixed rules — mixing them up is a reliable way to produce errors.
Group 1: U-verbs (五段動詞)
U-verbs have their dictionary form ending in various consonant + u sounds. The final syllable determines exactly how the ending changes before た is attached:
| Ending | Dictionary Form | た Form | Rule |
|---|---|---|---|
| く | 書く | 書いた | く → いた |
| ぐ | 泳ぐ | 泳いだ | ぐ → いだ |
| す | 話す | 話した | す → した |
| つ | 待つ | 待った | つ → った |
| う | 買う | 買った | う → った |
| る (u-verb) | 帰る | 帰った | る → った |
| む | 飲む | 飲んだ | む → んだ |
| ぶ | 飛ぶ | 飛んだ | ぶ → んだ |
| ぬ | 死ぬ | 死んだ | ぬ → んだ |
Group 2: Ru-verbs (一段動詞)
Ru-verbs end in る. Simply remove る and add た. This is the simpler of the two main groups:
| Dictionary Form | た Form |
|---|---|
| 食べる | 食べた |
| 見る | 見た |
| 起きる | 起きた |
Irregular Verbs
There are only two truly irregular verbs in Japanese. These must be memorized:
| Dictionary Form | た Form |
|---|---|
| する (to do) | した |
| くる (to come) | きた |
い-Adjectives
Remove the final い and add かった. Note the important exception for いい:
| Dictionary Form | Past Form |
|---|---|
| 高い | 高かった |
| 面白い | 面白かった |
| いい | よかった (irregular — not いかった) |
な-Adjectives and Nouns
Add だった directly after the な-adjective stem or noun:
| Dictionary Form | Past Form |
|---|---|
| 元気だ | 元気だった |
| 学生だ | 学生だった |
Example Sentences
Daily Activities
昨日、映画を見た。
Kinou, eiga wo mita.
Yesterday, I watched a movie.
朝ごはんを食べた。
Asagohan wo tabeta.
I ate breakfast.
日本語を勉強した。
Nihongo wo benkyou shita.
I studied Japanese.
友達に電話した。
Tomodachi ni denwa shita.
I called a friend.
Past States and Conditions
彼女は学生だった。
Kanojo wa gakusei datta.
She was a student.
子供の頃、猫が好きだった。
Kodomo no koro, neko ga suki datta.
When I was a child, I liked cats.
先生は親切だった。
Sensei wa shinsetsu datta.
The teacher was kind.
その店は静かだった。
Sono mise wa shizuka datta.
That shop was quiet.
Adjectives in Past Tense
昨日の天気は良かった。
Kinou no tenki wa yokatta.
Yesterday's weather was good.
その映画は面白かった。
Sono eiga wa omoshirokatta.
That movie was interesting.
試験は難しかった。
Shiken wa muzukashikatta.
The exam was difficult.
Movement and Completed Actions
去年、日本に行った。
Kyonen, Nihon ni itta.
Last year, I went to Japan.
先週、友達に会った。
Senshuu, tomodachi ni atta.
Last week, I met a friend.
電車で来た。
Densha de kita.
I came by train.
Common Mistakes
Mistake 1: Using the Dictionary Form for a Past Event
❌ 昨日、映画を見る。
✅ 昨日、映画を見た。
When a sentence describes a past event, you must use the た form, not the dictionary form. In Japanese, the dictionary form expresses present habit or future intention. Pairing 昨日 (yesterday) with a present-form verb creates a logical contradiction that sounds immediately wrong to native speakers. The tense marker at the end of the sentence must match when the event actually happened.
Mistake 2: Adding だった to an い-Adjective
❌ 昨日は忙しいだった。
✅ 昨日は忙しかった。
い-Adjectives conjugate on their own — drop the final い and add かった. Do not attach だった. The copula だ (and its past form だった) is reserved for な-adjectives and nouns. Beginners often assume all past tense uses だった — a reasonable instinct, but one that breaks down entirely with い-adjectives.
Mistake 3: Using かった with a な-Adjective
❌ 彼女は元気かった。
✅ 彼女は元気だった。
な-Adjectives do not conjugate like い-adjectives. They use the copula だ, which becomes だった in the past. Never apply the い-adjective ending かった to a な-adjective. A reliable test: if a word takes な when directly modifying a noun (e.g., 元気な人), it is a な-adjective and takes だった in the past.
Mistake 4: Forgetting the Irregular Form よかった
❌ 天気はいかった。
✅ 天気はよかった。
The adjective いい (good) is irregular. While the standard pattern replaces い with かった, いい does not become いかった — it becomes よかった. This is because いい is historically derived from よい (good) and retains the root よ in all conjugated forms. Memorize よかった as its own word; it comes up constantly in real conversation.
Mistake 5: Confusing the て-Form with the た-Form
❌ ご飯を食べて。(intending to say "I ate")
✅ ご飯を食べた。
The て-form and た-form share the same conjugation base in Group 1 verbs — they differ only in the final sound. The て-form connects clauses or signals requests; it does not mark a completed past event. To state that an action is finished, use た as the sentence-ending predicate.
Cultural Notes
In casual conversation, た is the default sentence-ender. When you finish something and report it — "I ate," "I arrived," "It was fun" — た is the expected choice among friends and family. Defaulting to polite ました in every sentence with a close friend would sound noticeably stiff.
た also does something unexpected: it captures a moment of sudden realization, even when that moment is happening right now. あった！(atta!) literally means "it was there" but is used in the present to say "I found it!" or "There it is!" Similarly, 分かった (wakatta) means "I understood" but functions as "Got it!" in response to instructions. This realization use of た is extremely common and goes well beyond marking past events.
Japanese written narratives — novels, manga, anime subtitles — rely almost exclusively on plain past た, even when describing sequential events. If you want to read naturally at any level, getting comfortable with た on the page is unavoidable. Manga with furigana and graded readers at N5–N4 are good places to start.
Watch how native speakers switch between た and ました depending on who they are addressing. This register-shifting is a core social skill in Japanese. Observing it in dramas or real conversations will help you internalize when each form fits far more effectively than studying rules in the abstract.
Related Grammar Points
- ない — Negative Form (Not) (Grammar N5)
- です — Polite Copula (Is/Am/Are) (Grammar N5)
- Past Tense of I-Adjectives — かった (Grammar N5)
- Na-Adjective (な形容詞) — Complete Usage Guide (Grammar N5)
- たことがある — Have Done Before (Grammar N5)
- より (yori) — Than: Making Comparisons in Japanese (Grammar N5)
JLPT Tips
For the JLPT N5 exam, expect to recognize and produce past tense forms across all word categories: Group 1 verbs, Group 2 verbs, irregular verbs, い-adjectives, な-adjectives, and nouns. The exam tests both comprehension and production, so passive recognition alone is not enough — you must construct the forms accurately under time pressure.
The most frequently tested items at N5 are the irregular verb conjugations (する → した; くる → きた) and the irregular い-adjective いい → よかった. Lock these in before exam day. They appear in both grammar and reading sections and cannot be derived from regular rules.
In reading passages, past tense markers help you map the timeline of events. Pay attention to time expressions like 昨日 (yesterday), 先週 (last week), 去年 (last year), and 子供の頃 (when one was a child). These almost always appear alongside た and confirm your reading of the timeline.
One technique that actually sticks: each evening, write three to five Japanese sentences in the past tense about what you actually did. What you ate, where you went, how you felt. Personal sentences beat abstract drills because the content is already in your memory. Review and correct them the next day, and た will start to feel automatic within a few weeks.
One last point: the て-form and た-form share the same conjugation base in Group 1 verbs, differing only in the final sound (て/で vs た/だ). Practicing one reinforces the other. Use that overlap — it makes both forms click faster and cuts your study time in half.