What is Plain Form?

Plain form, also known as dictionary form or informal form, refers to the basic, unmodified version of a Japanese verb, adjective or grammatical structure. By mastering the plain form, learners develop a strong foundation for constructing more complex sentences and expressing various levels of politeness.

Plain Form Verbs: The Basics

Japanese verbs fall into three main categories: Group 1 (う-verbs), Group 2 (る-verbs), and Group 3 (irregular verbs). Each group follows a specific conjugation pattern in plain form. Let’s explore these patterns:

Group 1 (う-verbs)

These verbs end with a character from the う-row, such as く, す, or む. To make them negative in plain form, replace the final character with its corresponding あ-row character, followed by “ない”. For example:

• 飲む (のむ, to drink) → 飲まない (のまない, not to drink)
• 書く (かく, to write) → 書かない (かかない, not to write)

Group 2 (る-verbs)

These verbs end with る, and are usually paired with a vowel sound from the い-row before る. To make them negative, simply replace る with “ない”. For example:

• 見る (みる, to see) → 見ない (みない, not to see)
• 食べる (たべる, to eat) → 食べない (たべない, not to eat)

Group 3 (Irregular Verbs)

There are only two primary irregular verbs in Japanese: する (to do) and 来る (くる, to come). Their negative plain forms are:

• する → しない (not to do)
• 来る (くる) → 来ない (こない, not to come)

Plain Form Adjectives

Japanese adjectives are divided into two groups: い-adjectives and な-adjectives. Let’s discuss how to use these adjectives in plain form:

い-adjectives

These adjectives end with the い sound, and their conjugation is straightforward. To make them negative in plain form, replace い with “くない”. For example:

• 高い (たかい, high) → 高くない (たかくない, not high)
• 暑い (あつい, hot) → 暑くない (あつくない, not hot)

な-adjectives

These adjectives use な to connect with a noun. In plain form, they remain unchanged, but to make them negative, add “じゃない” after the adjective. For example:

• 静か (しずか, quiet) → 静かじゃない (しずかじゃない, not quiet)
• 元気 (げんき, energetic) → 元気じゃない (げんきじゃない, not energetic)

Expanding Your Japanese Grammar: Plain Form Applications

Beyond simple sentence construction, plain form is instrumental in various advanced grammar structures such as:

• て-form conjunctions
• Conditional sentences
• Passive and causative forms
• Expressing desire, probability, and intention

By becoming proficient in plain form, you will unlock a deeper understanding of Japanese grammar and improve your language skills significantly.