Masu Form (Polite)ます形
The masu form (ます形) is polite Japanese. It’s the first verb form most learners study, used in all formal and semi-formal situations: shops, offices, classrooms, and with anyone you don’t know well. Building it requires knowing the verb’s group and extracting the correct stem.
The masu form (ます形) is polite Japanese. It’s the first verb form most learners study, used in all formal and semi-formal situations: shops, offices, classrooms, and with anyone you don’t know well. Building it requires knowing the verb’s group and extracting the correct stem.
How to form the masu stem
The process differs by verb group. For godan verbs, change the final -u row kana to the corresponding -i row kana, then add ます: 書く → 書き + ます = 書きます. For ichidan verbs, drop -ru and add ます: 食べる → 食べ + ます = 食べます. For する, it becomes します. For 来る, it becomes 来ます (kimasu).
Godan: the -i shift
Every godan ending has an -i counterpart: く→き, ぐ→ぎ, す→し, つ→ち, ぬ→に, ぶ→び, む→み, る→り, う→い. Examples: 泳ぐ→泳ぎます, 死ぬ→死にます, 飛ぶ→飛びます.
Ichidan: just drop -ru
The simplest rule in Japanese: 見る→見ます, 寝る→寝ます, 教える→教えます. No vowel shifting, no exceptions.
The four masu conjugations
The masu form itself conjugates into four patterns that cover all polite tenses. Using 書きます as the example: Non-past affirmative: 書きます (I write / I will write). Non-past negative: 書きません (I don’t write). Past affirmative: 書きました (I wrote). Past negative: 書きませんでした (I didn’t write). These four forms handle 90% of polite conversation.
When to use masu form
Use masu form with anyone you’re not close friends with. This includes: strangers, coworkers, customers, teachers, older people, and anyone you’ve just met. Masu form is also the default in public speaking, interviews, and customer service. Even among friends, some people prefer masu form if the relationship is still developing.
Masu form in questions
Add か to make polite questions: 食べますか (Will you eat?), 分かりましたか (Did you understand?). In very polite contexts, rising intonation alone (without か) also works.
Masu stem as a noun
The masu stem (the part before ます) often functions as a noun: 休み (yasumi, rest/holiday), 始まり (hajimari, beginning), 帰り (kaeri, return). This is a useful pattern for building vocabulary.
Masu form conjugation — all 4 tenses
| Verb | Group | ます (non-past) | ません (neg) | ました (past) | ませんでした (past neg) |
|---|---|---|---|---|---|
| 書く | Godan | 書きます | 書きません | 書きました | 書きませんでした |
| 話す | Godan | 話します | 話しません | 話しました | 話しませんでした |
| 待つ | Godan | 待ちます | 待ちません | 待ちました | 待ちませんでした |
| 飲む | Godan | 飲みます | 飲みません | 飲みました | 飲みませんでした |
| 買う | Godan | 買います | 買いません | 買いました | 買いませんでした |
| 食べる | Ichidan | 食べます | 食べません | 食べました | 食べませんでした |
| 見る | Ichidan | 見ます | 見ません | 見ました | 見ませんでした |
| する | Irreg. | します | しません | しました | しませんでした |
| 来る | Irreg. | 来ます | 来ません | 来ました | 来ませんでした |
Example sentences
毎日日本語を勉強します。
Mainichi nihongo o benkyou shimasu.
I study Japanese every day.
すみません、英語を話しますか。
Sumimasen, eigo o hanashimasu ka.
Excuse me, do you speak English?
Polite question to a stranger
昨日は何も食べませんでした。
Kinou wa nani mo tabemasendeshita.
I didn’t eat anything yesterday.
Past negative polite
もう帰りますか。
Mou kaerimasu ka.
Are you leaving already?
帰る is godan → 帰ります
先生が来ました。
Sensei ga kimashita.
The teacher has arrived.
来る → 来ます (ki-masu), past: 来ました
週末は何をしますか。
Shuumatsu wa nani o shimasu ka.
What will you do on the weekend?
Common mistakes
食べるます (tabeRUmasu)
食べます (tabemasu)
For ichidan verbs, you must DROP -ru before adding ます. Don’t stack them.
書くます (kakUmasu)
書きます (kakimasu)
For godan verbs, change the -u kana to -i kana before adding ます. く→き, not く+ます.
来ます (kumasu)
来ます (kimasu)
The kanji 来 is read き (ki) in masu form, not く (ku). This is one of the irregular readings you must memorize.
Frequently asked questions
Is masu form more "correct" than dictionary form?
No. Neither form is more correct — they’re different registers. Masu form is polite, dictionary form is casual. Using masu form with close friends sounds stiff and distant; using dictionary form with a boss sounds rude. Choose based on the social situation, not "correctness."
Can I always use masu form to be safe?
In conversation, yes — masu form is never rude. But you cannot use masu form inside relative clauses (日本語を話します人 is wrong), before grammar structures like ～つもり or ～ことがある, or in academic/journalistic writing. You need dictionary form for those contexts.
What about ～ませんか as an invitation?
～ませんか is a polite invitation pattern: 一緒に食べませんか (Won’t you eat together? = Would you like to eat together?). Despite being grammatically negative, it’s a positive invitation. This is one of the most useful polite patterns in Japanese.
What is the ます form of 書く?
書く → ?