A is B with です

A は B です A wa B desu A is B

A は B です (A wa B desu) means "A is B". です never changes, and there is no "a" or "the", so English "be" takes your students time.

Level: JLPT N5, beginner
Type: Sentence basics
English links: the verb be, articles, subject-verb agreement

What it means

This is the first sentence most of us learn. 私は先生です means "I am a teacher". A is the topic, the thing you are talking about. B is what you say about it. です at the end makes the sentence polite.

The は after the topic is written with the character は, but you say it "wa". It means something like "as for A". So the sentence is really "as for me, teacher".

です does not change. 私は先生です, 彼は先生です and 私たちは先生です all end the same way. There is no am, is or are, and no "a" or "the". 先生 can be "a teacher", "the teacher" or "teachers".

When everyone knows the topic, Japanese drops it. You introduce yourself with 田中です, with no 私は. And because は only means "as for", 私はラーメンです in a restaurant means "I'll have the ramen", not "I am ramen". Keep that one in mind, because you will hear it in English too.

How to build it

Pattern	How it works
A は B です A wa B desu	Polite. B is a noun. です is the same for I, you, he, she and they.
B です B desu	Drop A when the listener knows it. 学生です: "(I) am a student."
A は B だ A wa B da	The plain form, with friends and family. Often dropped in casual speech.

Examples

私は英語の先生です。 watashi wa eigo no sensei desu. I am an English teacher.
田中さんは数学の先生です。 tanaka-san wa suugaku no sensei desu. Mr Tanaka is a maths teacher.
今日は月曜日です。 kyou wa getsuyoubi desu. Today is Monday.
あの人は校長先生です。 ano hito wa kouchou-sensei desu. That person is the principal.
私はラーメンです。 watashi wa raamen desu. I'll have the ramen. (when you order)

How English says it

English uses the verb "be" for this sentence. "Be" changes with the subject: I am, you are, she is, they are. It also changes for the past: was, were.

English also needs things that Japanese leaves out. It needs a subject in every sentence: "It is Monday", not "Is Monday". And a single countable noun after "be" needs "a" or "the": "I am a teacher", not "I am teacher".

Why it can make English hard

Japanese has no articles. "I am teacher" and "He is student" are some of the most common errors you will hear in the first year.
です never changes, so am, is and are take practice. Many students write "My parents is teachers" long after they know the rule.
Japanese drops the topic when it is clear. Some learners do the same in English and answer "Is my friend" or "Is Monday".
は means "as for", not "equals". A word-for-word translation gives sentences like "I am ramen" or "Today is curry" (今日はカレーです, "we're having curry today").

Mistakes you will hear

I am teacher. I am a teacher. 先生です has no article. A job after "be" needs "a".
My parents is teachers. My parents are teachers. です is the same for every subject, so the student does not change "is".
A: Who is that? B: Is my friend. A: Who is that? B: That's my friend. The Japanese answer is just 友達です. English needs a subject.
I am ramen. I'll have the ramen. A word-for-word 私はラーメンです. English uses a verb to order food.

In the classroom

Give each student a job card. They stand and say "I am a doctor", "I am an artist". The class holds up a hand when they hear a missing "a". It is quick and it sticks.
Make three columns on the board: am, is, are. Call out subjects (my mother, we, Ken and Yui, I) and students point to the right column.
Show 田中です and ask how English says it. Then make a rule for the class: every English sentence needs a subject, even when Japanese does not.
Use the ramen sentence as a warm-up. Students laugh at "I am ramen", and then they remember that は is not "is".

Practice

Try each one, then open it to check.

1. Fill the gap: 私＿学生です。 (I am a student.)

Answer: は (wa)

私 is the topic, so it takes は. Say it "wa".
2. Translate: 山田さんは医者です。

Answer: Ms Yamada is a doctor. (or Mr Yamada)

English needs "is" and the article "a". さん can be Mr or Ms, so use the context.
3. A student writes "She are student." Fix it.

Answer: She is a student.

She takes "is", and a single job noun needs "a".
4. Translate into Japanese: Today is Friday.

Answer: 今日は金曜日です。

Today is the topic with は, and です ends the sentence.