There is one verb that I’m going to introduce immediately: the auxiliary verb (です). In English, we use the auxiliary verb to help us with verb tense. For instance, we say “I am leaving”, not “I leaving”, or “this is a pen”, not “this a pen”. In Japanese, the auxiliary verb is formally called the “assertive auxiliary verb” and is used to declare what something is. It is bold in the sentence below.
学生です。
[I am, he/she is] a student.
Note that periods in Japanese are represented by a small bubble (。) instead of a dot.
In English, when we use an auxiliary verb we must also add a pronoun, e.g. we can’t say “Is a student”, we must say “He is a student”. This is the same in Japanese—we need a topic for the sentence. The difference is that once the sentence topic is defined it does not need to be repeated. The following, for instance, is acceptable in Japanese:
Is John a student? Yes, is a student.
In English we would need to reply, “Yes, he is a student” despite the fact that we know “he” is the subject of the sentence from the question.
は is the particle that defines the topic of the sentence (when used as the topic particle the pronunciation is わ not は). It is the most fundamental particle in the language because it is present in every sentence even if it is not explicitly stated or repeated.
Now, remembering that every sentence ends with a verb and that the particle always follows the word or phrase that it is defining, we have the below as the most basic sentence structure.
【TOPIC】は【NOUN】です。
The most literal translation of the topic particle is “as for”. Remembering this will help you when the particle is used to define more abstract topics than mere pronouns.
私は学生です。
As for I, am a student.
In English, the auxiliary verb transforms depending on the pronoun:
I am a student.
He is a student.
We are students.
This is not the case in Japanese; it’s all much simpler.
私は学生です。
As for I, am a student.
彼は学生です。
As for he, is a student.
私たちは学生です。
As for we, are students.
You might also have noticed that nouns in Japanese do not have a plural form (the word for student does not change in any of the above sentences). With a few exceptions, plural forms of words in Japanese do not exist (yup, it’s a tough one to get your head round at first).
As stated in the introduction, all verbs in Japanese have two forms: the standard form (sometimes referred to as the “casual” form) and the honorific (“polite” form). In this guide I will use the terms “standard” and “polite” to denote the two different forms.
です is the polite form of the auxiliary verb. You will hear it everywhere, every day. だ is the standard form. The conjugation and grammatical usage is different, but they mean exactly the same thing.
彼は学生です。
He is a student.
彼は学生だ。
He is a student.
Both sentences can only be written as “He is a student” in English—the nuance of “polite” and “standard” form is lost in translation (at least when it comes to simple sentences like the above). Let’s look at the negative, simple past, and simple past negative tense of the auxiliary verb.
The Negative
Form
Present
Negative
Polite
です
ではありません
Standard
だ
ではない
We simply put the negative form of the auxiliary verb at the end of the sentence to make it negative.
彼は 学生ではありません。
He is not a student.
彼は 学生ではない。
He is not a student.
While the above sentences are grammatically correct, in conversation Japanese speakers will often replace では with じゃ, so we end up with:
彼は 学生じゃありません。
He is not a student.
彼は 学生じゃない。
He is not a student.
じゃ is more colloquial and rolls off the tongue far more easily than では.
The Past
Form
Present
Past
Polite
です
でした
Standard
だ
だった
彼は 学生でした。
He was a student.
彼は 学生だった。
He was a student.
The Past Negative
The conjugation is the same as for the negative, but we replace ない with なかった for the standard form. For the polite form we simply add でした (the past polite form of the auxiliary verb) to the negative form.
Form
Present
Past Negative
Polite
です
ではありませんでした
Standard
だ
ではなかった
彼は 学生ではありませんでした。
He was not a student.
彼は 学生ではなかった。
He was not a student.
As with the negative, we can also replace the では with じゃ to get the following:
彼は 学生じゃありませんでした。
He was not a student.
彼は 学生じゃなかった。
He was not a student.
Of course, armed with our topic particle and auxiliary verb, we can change the topic and the noun to create different sentences.