Desu vs Masu in Japanese: Meaning and Differences

2026/06/20

です and ます are two of the very first things you meet when learning Japanese. The good news is that the desu vs masu difference is far simpler than it looks.

This guide breaks down what each word means, how it works, and when to use it. 

Desu vs Masu: Key Differences

When people look up desu vs masu, they usually expect two rival words. They aren’t rivals at all. です and ます attach to different types of words, and they often appear in the very same sentence.

Here’s the heart of Japanese desu vs masu in one line:

• です follows nouns and adjectives
• ます attaches to verbs

Both sit at the end of a sentence, and both add politeness. So the simplest way to settle masu vs desu is to look at the word right in front of it: a noun or an adjective takes です, an action verb takes ます. That’s basically the whole rule. Everything below just shows you how it plays out.

What Does Desu Mean in Japanese?

To understand the desu meaning, think of です as the polite version of “to be” (is / am / are). Grammatically it’s a copula: a word that links a subject to a description or an identity.

• 私は学生です。  I am a student.
• これは本です。  This is a book.

So what is desu in Japanese, in practice? It’s the word that completes a sentence built around a noun or an adjective:

[Subject] は [noun / adjective] です。

です works with both adjective types, but slightly differently:

• な-adjectives take です directly, as in 静かです (it’s quiet) — and there’s a whole set of these to learn at N5 level.
• い-adjectives keep their own ending and add です only for politeness: 暑いです (it’s hot), never 暑です.

That second point is worth pausing on. With an い-adjective, です isn’t doing the “to be” job, the adjective already carries that meaning. です is there purely to sound polite.

A quick word on register in desu japanese: the casual equivalent of です is だ (da). 学生だ means the same as 学生です, just informal. As a beginner, you can safely default to です.

Conjugating です is regular:

• Present: です (is)
• Negative: じゃないです / じゃありません (is not)
• Past: でした (was)
• Past negative: じゃなかったです (was not)

What Does Masu Mean in Japanese?

The masu meaning in Japanese is different in nature: ます is a polite ending that attaches to a verb, so you never use it on its own.

To use masu in japanese, you change a verb to its stem and then add ます:

• 食べる (taberu) → 食べます to eat
• 行く (iku) → 行きます to go
• 見る (miru) → 見ます to see

How you form that stem depends on the verb group:

• Group 1 (u-verbs): change the final -u sound to -i, then add ます. 書く → 書きます, 読む → 読みます.
• Group 2 (ru-verbs): drop る and add ます. 食べる → 食べます.
• Group 3 (irregular): just memorise them. する → します, 来る → 来ます.

One thing surprises beginners: the ます-form covers both present and future. Japanese has no separate future tense, so 飲みます can mean “I drink” or “I will drink” depending on time words like 毎日 (every day) or 明日 (tomorrow).

Like です, ます conjugates cleanly:

• Present: ます (do / will do)
• Negative: ません (don’t)
• Past: ました (did)
• Past negative: ませんでした (didn’t)

When to Use Desu vs Masu

The honest answer to when to use desu vs masu is that you rarely choose between them. You use both, based on the words in your sentence. Because they cover different word types, they live together happily:

私は学生で、毎日勉強します。 I am a student and study every day.

Here です (in its connecting form で) handles the noun 学生, and ます handles the verb 勉強する. Same sentence, both forms.

What you actually decide is the politeness level. です・ます is the polite register, sitting between plain speech (だ and dictionary verbs) and full keigo. Use it with:

• people you’ve just met
• anyone older than you, teachers, or your boss
• shops, offices, and professional settings

You can drop to casual forms with close friends and family. When in doubt, stay polite. です・ます is always safe, and it’s the base every learner builds on. 

Three mistakes to avoid:

• Don’t put です on a verb: 食べるです is wrong → 食べます.
• Don’t double up: 行きますです is wrong → 行きます.
• Don’t drop the ending where it’s needed: 私は学生 is incomplete → 私は学生です.

If you’re mapping out your first months, a structured N5 roadmap leans on these forms quickly, and after 12 months of consistent practice they become second nature.

Desu and Masu Difference: Practice Exercises

Test the desu vs masu difference with a quick drill. Pick です or ます for each blank, then check your answers below.

1. これは猫＿＿。 (This is a cat.)
2. 毎日日本語を勉強し＿＿。 (I study Japanese every day.)
3. 天気はいい＿＿。 (The weather is good.)
4. 明日学校に行き＿＿。 (I will go to school tomorrow.)
5. あの人は先生＿＿。 (That person is a teacher.)
6. この部屋は静か＿＿。 (This room is quiet.)
7. 私は毎朝コーヒーを飲み＿＿。 (I drink coffee every morning.)
8. あの店は高い＿＿。 (That shop is expensive.)
9. 今、家にい＿＿。 (I’m at home now.)
10. これは私のかばん＿＿。 (This is my bag.)

Answers: 

1. です (noun)
2. ます (verb)
3. です (い-adjective)
4. ます (verb)
5. です (noun)
6. です (な-adjective)
7. ます (verb)
8. です (い-adjective)
9. ます (verb: いる → います)
10. です (noun).

Ready to turn this into real sentences with audio and feedback from native teachers? Explore our beginner courses at Nihongo Online School.