です (desu) and ます (masu) in Japanese

Your first Japanese sentences will often end in one of two ways. Some close with です (desu). Others contain a verb ending in ます (masu).

They may look like interchangeable ways to sound polite, but they are not. The choice depends on the kind of information you want to communicate.

By the end of this lesson, you will be able to look at an idea and decide whether it describes what something is or tells what someone does. That decision tells you whether you need です (desu) or a verb in ます (masu).

Two paths for closing a sentence

Use です (desu) after a noun or certain kinds of description. Use a verb ending in ます (masu) when you express an action politely.

The first sentence answers “What are you?” The second answers “What do you do?”

です (desu) for identities

After a noun, です (desu) presents an identity, profession, nationality, or category politely.

In these sentences, です (desu) resembles forms of “be”. It is still better not to memorize it as an exact translation of the English verb. Its main job here is to close a noun description politely.

です (desu) for descriptions

です (desu) also follows words that describe qualities.

静か (shizuka) means quiet. It is not an action. It describes the place, so the sentence ends in です (desu).

You may also hear おいしいです (oishii desu), it is delicious. Here です (desu) adds politeness to the description.

ます (masu) belongs to the verb

ます (masu) is not freely attached to any word at the end of a sentence. It is part of the polite form of a verb.

The actions are eating, working, and reading. Each verb already contains its polite ending.

Do not add です (desu) after ます (masu)

A sentence takes one path or the other.

学生です (gakusei desu) is correct because 学生 (gakusei), student, is a noun.

食べます (tabemasu) is correct because it is already a polite verb.

食べますです (tabemasu desu) is incorrect. It adds two polite endings where only one is needed.

Decide from the question

When you are unsure, ask yourself one of these questions:

Kind of information	Mental question	Usual ending
Identity or category	What is it?	です (desu)
Quality or state	What is it like?	です (desu)
Action	What does someone do?	verb in ます (masu)

Select the two sentences that use their endings correctly:

Why the u can be hard to hear

In natural speech, the final vowel in です (desu) and ます (masu) is often very weak. です (desu) can sound close to “des”, and ます (masu) close to “mas”.

You do not need to force this reduction immediately. Pronouncing a soft u is correct and understandable. Your ear will become familiar with the natural rhythm over time.

Describe and act

Imagine two columns about yourself. Put three identities or descriptions in the first: student, teacher, quiet, busy. Put three actions in the second: study, work, read.

End the ideas in the first column with です (desu) and turn the actions in the second into verbs with ます (masu). This makes the difference a decision about meaning rather than two endings learned by memory.