ます Form vs Dictionary Form: Japanese Verb Basics Explained

You open your textbook and see 食べます (tabemasu) — then your dictionary shows 食べる (taberu). Same verb, completely different ending. Which one do you actually use when you speak?

This is one of the first real confusions for Japanese beginners, and it trips up even intermediate learners who never got a clear explanation. In this guide you’ll learn exactly what the ます form and the dictionary form are, when each one belongs, how to switch between them for every verb group, and which other verb forms branch out from the dictionary form. By the end, you’ll know which form to reach for in any situation — and why.

At a Glance: ます Form vs Dictionary Form

What Is the Dictionary Form?

The dictionary form (辞書形, jisho-kei) is the base, citation form of a Japanese verb — the form you find when you look a word up in a dictionary. Every single Japanese verb ends in the sound -u when in this form: 書く (kaku, write), 飲む (nomu, drink), 食べる (taberu, eat), する (suru, do). Without exception.

Think of it the way English speakers think of the infinitive “to eat” or “to go” — except in Japanese the “to” is already baked into the verb ending. You don’t add anything; this is the base form. Native speakers use it constantly in casual, everyday conversation with friends and family, and it is the launching pad for almost every other verb form you will ever learn.

What the dictionary form looks like:

When native speakers use the dictionary form in conversation:

• 友達と映画を見る。(Tomodachi to eiga wo miru.) — I’m watching a movie with friends. [casual, present/future]
• 明日、公園に行く？(Ashita, kouen ni iku?) — Are you going to the park tomorrow? [casual question]
• 毎朝コーヒーを飲む。(Maiasa koohii wo nomu.) — I drink coffee every morning. [casual habit]

⚠️ Important note for beginners: Even though native speakers use the dictionary form freely, beginners are usually taught to avoid it with strangers or in formal settings. Until you have a feel for Japanese social context, the ます form is your safer default.

What Is the ます Form?

The ます form (ます形, masu-kei) is the polite, “textbook” form of a Japanese verb. It always ends in ます (-masu) in the present/future affirmative. When you study Japanese in a classroom or self-study app, you’ll almost certainly learn ます form first — because it is socially safe to use with virtually anyone you don’t know well.

The ます form doesn’t just mean “polite present tense.” It has a full set of conjugations that mirror the dictionary form in meaning but wrap everything in a layer of social courtesy:

Examples of ます form in context:

• 毎日日本語を勉強します。(Mainichi nihongo wo benkyou shimasu.) — I study Japanese every day.
• 昨日は映画を見ませんでした。(Kinou wa eiga wo mimasendeshita.) — I didn’t watch a movie yesterday.
• 一緒に食べましょう！(Issho ni tabemashou!) — Let’s eat together!

Yuka

When I first moved to Tokyo and had to talk to my landlord, I used ます form for everything — 分かりました、よろしくお願いします。It felt a bit stiff, but it was always correct!

Rei

That’s the best strategy for beginners. Even if ます form sounds a little formal with close friends, no one will be offended. If you use plain form too early with a stranger, it can come across as rude.

When to Use Each Form

Choosing between ます form and dictionary form is almost entirely about social context and relationship, not about grammar rules. Here is a practical breakdown:

The golden rule for beginners: When in doubt, use ます form. It is never rude. It may occasionally sound overly formal in a casual context, but that is a minor problem. Using plain form with someone who expects politeness is a far more serious social mistake.

Group 1, 2, 3 Verbs: How to Switch Between Forms

Japanese verbs are divided into three groups based on how they conjugate. The good news: once you know which group a verb belongs to, converting between dictionary form and ます form is mechanical and predictable.

Group 2 (ru-verbs / 一段動詞) — Easiest to convert

Group 2 verbs end in -eru or -iru in the dictionary form. To make ます form: drop the る and add ます.

Group 1 (u-verbs / 五段動詞) — One step more

Group 1 verbs end in various -u sounds (ku, gu, su, tsu, nu, bu, mu, ru*). To make ます form: change the final -u sound to its -i sound equivalent, then add ます.

*Note: Some verbs ending in -ru are actually Group 1 (e.g., 帰る kaeRU = return, ます form 帰ります). These must be memorized individually.

Group 3 (Irregular verbs) — Just memorize two

There are only two irregular verbs in Japanese. Memorize them and you’re done.

💡 Many action nouns pair with する to become compound verbs: 勉強する (benkyou suru, to study), 運動する (undou suru, to exercise). These all follow the same Group 3 pattern.

Yuka

I always mix up 帰る (kaeru, return home) — it ends in -ru but it’s Group 1! I kept conjugating it like Group 2 and dropping the る to get 帰ます, which is completely wrong. The correct form is 帰ります.

Rei

That’s the classic trap! Verbs like 帰る, 走る (hashiru, run), 知る (shiru, know), and 切る (kiru, cut) all end in -ru but are Group 1. Unfortunately there’s no single rule that catches them all — the safest approach is to memorize these common exceptions as you encounter them.

Forms Built on the Dictionary Form

Here’s why the dictionary form is so important: most of the verb forms you’ll learn next all derive from it. The ます form is largely a polite endpoint. The dictionary form is a hub with roads leading in every direction.

Here are three essential forms that branch from the dictionary form:

1. The ない Form (Negative Plain)

Used to say “don’t” or “doesn’t” in casual speech, and as the base for many grammar patterns.

• Group 2: drop る, add ない → 食べる → 食べない (tabenai, don’t eat)
• Group 1: change -u to -a, add ない → 書く → 書かない (kakanai, don’t write)
• Group 3: する → しない, 来る → 来ない

2. The て Form (Connecting Form)

The て form (te-form) is arguably the most versatile form in all of Japanese. It connects actions (“I ate and then…”), makes requests (食べてください, please eat), and builds dozens of grammar patterns like ～ている (ongoing action), ～てもいい (may I), ～てしまう (regrettably did). It derives from the dictionary form stem following predictable spelling changes.

3. The た Form (Plain Past)

The た form is the casual past tense. It follows the same spelling pattern as the て form — wherever て appears, replace it with た.

• 食べる → 食べた (tabeta, ate)
• 書く → 書いた (kaita, wrote)
• 飲む → 飲んだ (nonda, drank)

💡 The big picture: Think of dictionary form as the root of a tree. ます form is one branch — important, but just one. ない, て, and た are other branches. Every advanced grammar pattern you learn will grow from this same root.

Common Mistakes English Speakers Make

These are the four mistakes that come up again and again with beginner English speakers learning Japanese verb forms:

Mistake 1: Using ます form inside grammar patterns

Mistake 2: Thinking dictionary form = past tense

In English, “I ate” is clearly past tense. Beginners sometimes assume 食べる must be past because “it sounds more abrupt.” It is not. 食べる is present/future plain form. Past is 食べた (plain) or 食べました (polite).

Mistake 3: Using plain form too early with new people

English has no grammatical formality distinction in verbs — “I eat” and “I eat (formally)” are the same. Japanese does not work that way. Using plain form with a stranger, teacher, or new colleague in Japan can come across as impolite or even aggressive. Always start with ます form and let the other person signal if casual speech is welcome.

Mistake 4: Misidentifying Group 1 verbs that look like Group 2

Several common Group 1 verbs end in -ru or -iru and look like Group 2 verbs to the eye. They must be memorized:

Which Form Should I Use? A Decision Flowchart

Not sure which form to reach for? Walk through this:

Are you using the verb as a GRAMMAR PATTERN (e.g., ~ことができる, ~ために, ~てもいい)?
  └─ Yes → Use DICTIONARY FORM (plain form is the grammar base)

Are you using the verb as a STANDALONE SENTENCE?
  └─ Yes → Who are you talking to?
              ├─ Stranger / teacher / boss / first meeting
              │    └─ Use MASU FORM  (食べます, 行きます)
              │
              ├─ Close friend / family member
              │    └─ Use DICTIONARY FORM  (食べる, 行く)
              │
              └─ Yourself (diary, inner monologue)
                   └─ Use DICTIONARY FORM  (食べる, 行く)

Are you writing a FORMAL EMAIL or BUSINESS DOCUMENT?
  └─ Yes → Use MASU FORM throughout

Are you reading MANGA / WATCHING ANIME?
  └─ Yes → Characters use DICTIONARY FORM — don't copy it in formal speech!

Yuka

My rule of thumb: I use ます form with anyone I’d use さん with. Once we’re on a first-name basis or nickname basis, I switch to plain form naturally.

Rei

That’s a great rule! And for grammar patterns, always go dictionary form no matter how polite you want to sound — the politeness comes from the ます at the very end of the sentence, not inside the grammar.

Quick Quiz: ます Form vs Dictionary Form

Choose the correct form for each situation. Answers below.

1. You’re telling your new Japanese teacher “I study Japanese every day.” Do you say: (a) 毎日日本語を勉強する or (b) 毎日日本語を勉強します?
2. You want to say “I can swim” using ～ことができる. Which form of 泳ぐ comes before ことができる: (a) 泳ぎます or (b) 泳ぐ?
3. Convert 飲む (nomu) to ます form. Is it: (a) 飲みます or (b) 飲ます?
4. Your close friend asks what you’re doing tonight. You want to say “Going to eat ramen.” Casual answer: (a) ラーメンを食べます or (b) ラーメンを食べる?
5. Is 帰る (kaeru, return home) a Group 1 or Group 2 verb, and what is its ます form?

Answers:

1. (b) 毎日日本語を勉強します — Talking to your teacher = polite context, use ます form.
2. (b) 泳ぐ — Grammar patterns attach to dictionary form: 泳ぐことができます (I can swim).
3. (a) 飲みます — Group 1: mu → mi + masu. (飲ます is wrong.)
4. (b) ラーメンを食べる — With close friends, casual dictionary form is natural and expected.
5. Group 1 — ます form is 帰ります (kaerimasu), not 帰ます. 帰る looks like a Group 2 verb but is a Group 1 exception — one of the most common ones, so memorize it early.

💬 How did you do? Drop a verb in the comments and try converting it — I’ll check your answer!

Want to practice these forms with a real teacher? Find a Japanese tutor on italki — trial lessons start under $10 and you’ll get real-time feedback on your conjugations.

Keep Learning

Now that you know the difference between ます form and dictionary form, you’re ready to go deeper. The て form is the next essential step — it unlocks dozens of grammar patterns:

あわせて読みたい

Te-Form Japanese: 10 Uses Every Learner Must Know Master the Japanese te-form: conjugation rules for all verb groups plus 10 essential uses including requests, ongoing actions, permission, and more.

あわせて読みたい

Nai-Form Japanese: How to Make Any Verb Negative Learn the Japanese nai-form (ない form) for all three verb groups. Covers negative present, past, requests (ないでください), obligation, and permission patterns.

あわせて読みたい

JLPT N4 Grammar Essentials: 12 Patterns You Must Know Master 12 essential JLPT N4 grammar patterns: てもいい, てはいけない, ようになる vs ようにする, んです, らしい, はずだ, and more. Clear rules with examples and JLPT-style quiz.