Mastering the Japanese Verb Conjugation (Te, Dictionary, Nai, Ta forms)

Written by Rahul Kumar Singh · Published 15 June 2026

Verbs form the backbone of Japanese sentences. Unlike languages with complex subject-verb agreement or numerous irregular forms, Japanese verbs follow highly systematic conjugation rules. Once you master the classifications and their matching patterns, you can conjugate almost any verb in the language. This guide provides an exhaustive breakdown of the three verb groups, followed by step-by-step instructions for conjugating them into the four essential forms: the Dictionary Form, the Te-form, the Nai-form, and the Ta-form.

To establish a solid foundation in Japanese communication, one must become comfortable with the concept of verb grouping. In English, we deal with past, present, and continuous tenses that often require memorizing irregular tables (e.g., go-went-gone, write-wrote-written). In Japanese, however, once you identify the group a verb belongs to, the conjugation is entirely predictable. There are virtually no exceptions outside of the two irregular verbs. This makes the language highly logical and structured for self-studiers. Whether you are aiming for daily conversations in Japan or preparing for the JFT-Basic exam, verb conjugation is the single most critical milestone you must pass.

Let's look at the foundational classification system. Verbs in Japanese are divided into three groups: Group 1 (U-verbs or Godan), Group 2 (Ru-verbs or Ichidan), and Group 3 (Irregular verbs). Group 1 verbs are characterized by having nine possible endings in their dictionary form. Group 2 verbs are simpler and always end in -ru preceded by an -i or -e sound. Group 3 consists of just two verbs: suru (to do) and kuru (to come). Understanding these distinctions is the absolute first step before you attempt any modifications.

Furthermore, mastering these verb groups will accelerate your overall learning curve. Once you know which group a verb belongs to, you can generate not only the plain past or negative forms but also conditional, potential, passive, and causative forms. This grammatical consistency is one of the most rewarding features of the Japanese language, enabling you to build complex sentences relatively early in your studies compared to other foreign languages.

1. Understanding the Three Verb Groups

Before you can conjugate a Japanese verb, you must identify which of the three verb groups it belongs to. Grouping is determined by the dictionary form's final syllable.

Group 1: U-Verbs (Godan Douji)

Group 1 verbs end in a dictionary vowel sound that is not preceded by "e" or "i" in most cases. Their dictionary endings are ~u, ~ku, ~gu, ~su, ~tsu, ~nu, ~bu, ~mu, or ~ru. Examples include: 買う (kau - to buy), 書く (kaku - to write), 泳ぐ (oyogu - to swim), 話す (hanasu - to speak), 待つ (matsu - to wait), 死ぬ (shinu - to die), 呼ぶ (yobu - to call), 飲む (nomu - to drink), and 取る (toru - to take).

Group 2: Ru-Verbs (Ichidan Douji)

Group 2 verbs always end in ~ru. Furthermore, the vowel sound immediately preceding the final ~ru is either "i" (known as Kami-Ichidan) or "e" (known as Shimo-Ichidan). Examples include: 食べる (taberu - to eat, ends in "e-ru"), 見る (miru - to see/watch, ends in "i-ru"), 起きる (okiru - to wake up), and 教える (oshieru - to teach).

Note: There are a few exceptions—verbs that end in ~iru or ~eru but actually conjugate as Group 1 (U-verbs). Common exceptions include 帰る (kaeru - to return), 入る (hairu - to enter), 走る (hashiru - to run), and 知る (shiru - to know). These must be memorized individually.

Group 3: Irregular Verbs

Group 3 consists of only two irregular verbs that you must memorize:

• する (suru) – to do. It conjugates to して (te-form), しない (nai-form), and した (ta-form).
• 来る (kuru) – to come. It conjugates to 来て (kite, te-form), 来ない (konai, nai-form), and 来た (kita, ta-form).

2. The Dictionary Form (Plain Present)

The Dictionary Form is the base form found in dictionaries. It is used in casual speech to express habitual actions or future intentions. In Japanese grammar, it is also called the plain present affirmative form. For example, 毎日水を飲む (Mainichi mizu wo nomu) means "I drink water every day" or "I will drink water." To make a dictionary form formal, we conjugate it to the polite ~masu form. For Group 1 verbs, change the final ~u sound to its corresponding ~i sound and add masu (e.g., 書く -> 書き + ます = 書きます). For Group 2 verbs, remove ~ru and add masu (e.g., 食べる -> 食べ + ます = 食べます).

Using the plain present form requires understanding conversational context. In casual Japanese, speaking with close friends or family, you will rarely hear the polite ~masu form. Instead, plain form rules. Conversely, in formal settings, using plain form can be perceived as rude or unprofessional. Therefore, learning to switch between plain and polite forms is crucial. Practice translating simple sentences in both forms to build speed and accuracy.

Furthermore, plain form is the building block for many complex sentence structures. For instance, relative clauses (clauses that modify nouns) always use the plain form. In the sentence "The book that I read" (私が読む本 - Watashi ga yomu hon), the verb "yomu" must be in the plain dictionary form. This means that even if you plan to speak politely using ~masu all the time, you still need to master the plain dictionary form to construct and understand complex sentences.

3. The Te-Form (Connecting Verbs & Requests)

The Te-form is one of the most versatile forms in Japanese. It is used to connect sentences, describe sequential actions, make requests, and indicate continuous actions. The rules for Group 1 verbs are detailed below:

• If the verb ends in う (u), つ (tsu), or る (ru), replace the ending with って (tte). Example: 買う (kau) -> 買って (katte); 待つ (matsu) -> 待って (matte); 取る (toru) -> 取って (totte).
• If the verb ends in む (mu), ぶ (bu), or ぬ (nu), replace the ending with んで (nde). Example: 飲む (nomu) -> 飲んで (nonde); 呼ぶ (yobu) -> 呼んで (yonde); 死ぬ (shinu) -> 死んで (shinde).
• If the verb ends in く (kaku), replace the ending with いて (ite). Example: 書く (kaku) -> 書いて (kaite). (Exception: 行く (iku) becomes 行って (itte)).
• If the verb ends in ぐ (gu), replace the ending with いで (ide). Example: 泳ぐ (oyogu) -> 泳いで (oyoide).
• If the verb ends in す (su), replace the ending with して (shite). Example: 話す (hanasu) -> 話して (hanashite).

For Group 2 verbs, the conjugation is simple: drop the final る (ru) and add て (te). Example: 食べる (taberu) -> 食べて (tabete); 見る (miru) -> 見て (mite).

4. The Nai-Form (Plain Negative)

The Nai-form is used in casual negative sentences and forms the basis for structures like "must not" (~te wa ikenai) or "have to" (~nakereba naranai). The rules are as follows:

• Group 1: Change the final vowel sound in dictionary form from the ~u column to the corresponding ~a column and add ない (nai). Example: 書く (kaku) -> 書か + ない = 書かない (kakanai). For verbs ending in a bare う (u), change the う to わ (wa) and add ない. Example: 買う (kau) -> 買わ + ない = 買わない (kawanai).
• Group 2: Drop the final る (ru) and add ない (nai). Example: 食べる (taberu) -> 食べない (tabenai); 起きる (okiru) -> 起きない (okinai).
• Group 3 (Irregular): する (suru) becomes しない (shinai); 来る (kuru) becomes 来ない (konai).

The Nai-form is also essential for expressing obligation using the common pattern なければなりません (nakereba narimasen). This structure literally means "if you do not do it, it will not do," translating directly to "must" or "have to." For example, 宿題をしなければなりません (Shukudai wo shinakereba narimasen) means "I must do my homework." Mastering the conjugation into Nai-form is therefore a prerequisite for expressing any mandatory daily action.

Additionally, the Nai-form is used to make polite requests not to do something using the pattern 〜ないでください (nai de kudasai). For instance, 写真を撮らないでください (Shashin wo toranaide kudasai) translates to "Please do not take photos." This is extremely common in public instructions, warnings, and safety signs across Japan, making the Nai-form highly practical for daily life survival.

5. The Ta-Form (Plain Past)

The Ta-form is the casual past tense. Fortunately, the conjugation rules for the Ta-form are identical to the Te-form, except that you replace て (te) with た (ta), and で (nde/ide) with だ (da). Examples:

• 買う (kau) -> 買った (katta)
• 飲む (nomu) -> 飲んだ (nonda)
• 書く (kaku) -> 書いた (kaita)
• 食べる (taberu) -> 食べた (tabeta)
• する (suru) -> した (shita)
• 来る (kuru) -> 来た (kita)

The Ta-form is also used in several essential grammatical structures. For instance, the pattern 〜たことがあります (ta koto ga arimasu) describes past experiences, translating to "have done something before." For example, 日本に行ったことがあります (Nihon ni itta koto ga arimasu) means "I have been to Japan before." It is also used in the conditional form 〜たら (tara) to express "if" or "when."

Finally, the combination pattern 〜たり〜たりします (tari tari shimasu) allows you to list multiple actions in no particular order. For example, 週末は映画を見たり、買い物をしたりします (Shuumatsu wa eiga wo mitari, kaimono wo shitari shimasu) means "On weekends, I do things like watching movies and shopping." This is an extremely useful pattern for describing daily activities or routines casually and naturally.

Practice Exercises

Test your understanding of the concepts discussed in this guide. Try to answer the questions below before checking the answer key at the bottom.

1. Conjugate 待つ (matsu) into the Te-form:
       a) 待って (matte)
       b) 待ちて (machite)
       c) 待んで (mande)
       d) 待ってて (mattete)
   
2. Conjugate 買う (kau) into the Nai-form:
       a) 買わない (kawanai)
       b) 買あない (kaanai)
       c) 買いない (kainai)
       d) 買わないない (kawanainai)
   
3. What is the Ta-form of する (suru)?
       a) した (shita)
       b) するた (suruta)
       c) して (shite)
       d) したが (shita-ga)
   
4. Conjugate 話す (hanasu) into the Nai-form:
       a) 話さない (hanasanai)
       b) 話しない (hanashinai)
       c) 話すない (hanasunai)
       d) 話したない (hanashitanai)
   
5. Convert 食べる (taberu) to the formal past polite form:
       a) 食べました (tabemashita)
       b) 食べたでした (tabetadeshita)
       c) 食べてました (tabetemashita)
       d) 食べましたた (tabemashitata)
   

Answer Key & Explanations

• Question 1: Correct Answer is a. 待つ ends in ~tsu, so we replace it with って to make 待って.
• Question 2: Correct Answer is a. Verbs ending in a bare う replace the う with わ before adding ない, so 買う becomes 買わない.
• Question 3: Correct Answer is a. する is an irregular verb whose plain past form is した.
• Question 4: Correct Answer is a. 話す is a Group 1 verb. We change the final -su sound to -sa and add nai, resulting in 話さない.
• Question 5: Correct Answer is a. To make the past polite form of Group 2, remove ru, add mashita, resulting in 食べました.

Rahul Kumar Singh

I build and write NihongoDoya. I'm a Japanese learner from Nepal — currently preparing for the JLPT N4 at a language school with native Japanese teachers — and I publish the study system I use myself, free for everyone. More about me · Say hello