Plain form in Japanese and how to make it

What is “plain form” in Japanese?

The plain form is one of the most widely-used conjugation forms in Japanese. As its name suggests, verbs, adjectives, and auxiliary verbs in this form are plain, namely not conjugated. In this blog post, I will explain the very basics of plain-formed words and also how to use them through example sentences.

Honestly speaking, explaining conjugation forms is not easy, as there are always gaps between native speakers and Japanese learners. Japanese has six different forms and Japanese native speakers learn all of them in school. However, what they learn is not exactly the same as what Japanese learners learn. The nai form is one example. Native speakers learn this form as a combination of a conjugated word and an auxiliary verb; often, Japanese learners learn it as one form. Additionally Japanese learners definitely learn more than six conjugation forms. This means, I cannot use the knowledge I got in school to explain conjugation forms. Fortunately, however, the plain form is common in the both learning ways. So, I hope my explanations are understandable and helpful for Japanese learners.

Then, let’s get started!

Contents

• Definition of plain form
• Verb in plain form
  • Example #1: how to use a plain-formed verb
  • Example #2: how to make a noun phrase with a plain-formed verb
• I-adjective in plain form
  • Example #3: how to use a plain-formed i-adjective
  • Example #4: how to make a noun phrase with a plain-formed i-adjective
• Na-adjective in plain form
  • Example #5: how to use a na-adjective at the end of a sentence
  • Example #6: how to make a noun phrase with a plain-formed na-adjective
• Summary

Definition of plain form

In Japanese, the plain form is called “shuushikei”. I’m not sure if this is well known among Japanese learners, but this name is very helpful to understand the concept behind the form. So, let me explain this name in detail based on its kanji.

• shuushikei – 終止形 (しゅうしけい) : a noun meaning ‘the plain form’ in Japanese.

The first two kanji characters mean ‘the end’; the last one means ‘form’, ‘type’, or such. From these three kanji characters, therefore, we can understand that “shuushikei” means ‘a form for the end’. And actually it is. A Japanese sentence normally ends with a plain-formed verb, adjective, or auxiliary verb. In addition, a clause, for example a clause modifying its following noun, also ends with a plain-formed word. So, we need to know this form well. Furthermore, words in the dictionary are plain formed. Also in this regard, this form is very important.

In the rest part of this blog post, I will explain a plain-formed verb, i-adjective, and na-adjective, one by one.

Verb in plain form

There are two different verb categories: u-verbs and ru-verbs. In principle, however, the plain-formed verbs always end with the “u” vowel. To know if a verb is in its plain form or not, therefore, we should check its last vowel.

Then, let me explain how to use a plain-formed verb through the following example sentence.

Example #1: how to use a plain-formed verb

Below are the new words used in the example sentence.

• watashi – 私 (わたし) : a pronoun meaning ‘I’ in Japanese.
• wa – は : a binding particle working as a case marker or topic marker. In the example, this is used after “watashi” to make the subject word in the sentence.
• kyou – 今日 (きょう) : a noun meaning ‘today’ in Japanese. This can also work as an adverb. In the example, it works as an adverb to say “today” in Japanese.
• kyoto – 京都 (きょうと) : a name of one of the most famous Japanese cities. This is a noun.
• ni – に : a case particle used to indicate a particular place which someone or something is in. In the example, this is used after “kyoto” to indicate the place which “watashi” is in. This particle is often translated into English as “in” or “at”.
• iru – いる : a verb used to express the existence of a living thing. In the example, this is used to express the existence of “watashi”. This is the plain form of this verb itself.

In this example, the verb, “iru”, is used in its plain form and placed at the end of the sentence. When we want to end a sentence with a verb, we need to use its plain form.

Example #2: how to make a noun phrase with a plain-formed verb

As I mentioned earlier, a clause modifying its following noun ends with a plain-formed verb. Let me explain this usage as follows.

Below is the new word used in the example phrase.

• ga – が : a case particle used to make the subject word or the object word in a sentence. In the example, this is used after “watashi” to make the subject in the clause.

This noun phrase can be broken down into the following two parts: “watashi ga iru” and “kyoto”. The first one is a clause modifying the noun, “kyoto”, and ends with the plain-formed verb, “iru”. A plain-formed verb can have a better connection with a noun, so is suitable for the end of a clause.

I-adjective in plain form

There are two different conjugation types for i-adjectives: the ku-conjugation and the shiku-conjugation. In principle, however, the plain-formed i-adjectives end with the “i” vowel. To know if an i-adjective is in its plain form or not, therefore, we should check its last vowel.

Then, let me explain how to use a plain-formed i-adjective through the following example sentence.

Example #3: how to use a plain-formed i-adjective

Below are the new words used in the example sentence.

• totemo – とても : an adverb of degree, meaning ‘very’, ‘much’, ‘so’, ‘quite’, or such in Japanese.
• utsukushii – 美しい (うつくしい) : an i-adjective meaning ‘beautiful’ in Japanese. This is the plain form of this i-adjective itself.

In this example, the i-adjective, “utsukushii”, is used in its plain form and placed at the end of the sentence. When we want to end a sentence with an i-adjective, we need to use its plain form.

Example #4: how to make a noun phrase with a plain-formed i-adjective

Next, then, let me explain how to make a noun phrase with a plain-formed i-adjective.

This noun phrase can be broken down into the following two parts: “totemo utsukushii” and “kyoto”. The first one can be considered as a clause modifying the noun, “kyoto”, and ends with the plain-formed i-adjective, “utsukushii”. A plain-formed i-adjective can have a better connection with a noun, so is suitable for the end of a clause. Honestly speaking, however, “totemo utsukushii” in this phrase works more like an adjective phrase rather than a clause.

Na-adjective in plain form

Na-adjectives have different forms at the end of a sentence and at the end of a clause. What Japanese learners call na-adjectives is normally ones used at the end of a clause.

Basically every na-adjective consists of one noun and one conjugative suffix. Most of their conjugations are subjected to those of the auxiliary verb, “da“. So, learning this auxiliary verb is very fruitful.

Then, let me explain how to use a na-adjective at the end of a sentence through the example below.

Example #5: how to use a na-adjective at the end of a sentence

Below is the new word used in the example sentence.

• kireida – 綺麗だ (きれいだ) : one conjugation of the na-adjective, “kireina“, which means ‘beautiful’ in Japanese. It has been conjugated to end the sentence naturally.

In this example, the na-adjective, “kireina”, is used. It has been conjugated to make the sentence-end sound natural. Probably “kireida” is known as the da-form of “kireina” among Japanese learners. For native speakers, however, this is the plain form of “kireida” itself. This is one gap between Japanese learners and native speakers.

Example #6: how to make a noun phrase with a plain-formed na-adjective

Next, then, let me explain how to use a noun phrase with a plain-formed na-adjective.

This noun phrase can be broken down into the following two parts: “totemo kireina” and “kyoto”. The first one can be considered as a clause modifying the noun, “kyoto”, and ends with the plain-formed na-adjective, “kireina”. A plain-formed na-adjective can have a better connection with a noun, so is suitable for the end of a clause. Honestly speaking, however, “totemo kireina” in this phrase works more like an adjective phrase rather than a clause.

Summary

In this blog post, I’ve explained the plain form with the example sentences. Let me summarize them as follows.

• Plain-formed verbs end with the “u” vowel. When we want to end a sentence with a verb or to make a clause, we need to use its plain form.
• Plain formed i-adjectives end with the “i” vowel . When we want to end a sentence with an i-adjective or to make a clause, we need to use its plain form.
• Plain formed na-adjetives end with the “na” sound. When we want to make a clause with a na-adjective, we need to use its plain form. When we want to end a sentence with a na-adjective, we need to conjugate it to its da form.

Hope my explanations are understandable and helpful for Japanese learners.