Dictionary Form (Plain Form) | Japanese Grammar Documentation

What is Dictionary Form?

Dictionary form (辞書形) is the basic, unconjugated form of a verb. It's called "dictionary form" because it's how verbs appear in dictionaries.

食べる (taberu) - eat
行く (iku) - go
する (suru) - do

Also called: plain form, basic form, u-form

When to Use Dictionary Form

1. Casual Conversations

With friends, family, people younger than you:

何食べる？
"What will you eat?"

映画見る？
"Will you watch a movie?"

明日行く
"I'll go tomorrow"

2. Inner Thoughts/Narrative

今日は何をしようかな...
"What should I do today..."

そろそろ帰る時間だ
"It's about time to go home"

3. Grammar Patterns

Many patterns require dictionary form:

食べることができる - can eat
行くつもりだ - intend to go
飲む前に - before drinking

4. Quoting/Reporting

彼は行くと言った
"He said he would go"

明日雨が降ると思う
"I think it will rain tomorrow"

5. Modifying Nouns

食べる人 - person who eats
行く時間 - time to go
読む本 - book to read

All Verb Groups in Dictionary Form

Godan Verbs

End in -u sounds:

書く (kaku) - write
読む (yomu) - read
話す (hanasu) - speak
買う (kau) - buy
待つ (matsu) - wait
遊ぶ (asobu) - play
飲む (nomu) - drink
帰る (kaeru) - return
泳ぐ (oyogu) - swim

Ichidan Verbs

End in -eru or -iru:

食べる (taberu) - eat
見る (miru) - see
寝る (neru) - sleep
起きる (okiru) - wake up
教える (oshieru) - teach
着る (kiru) - wear
出る (deru) - go out
開ける (akeru) - open

Irregular Verbs

する (suru) - do
来る (kuru) - come

Polite vs Plain

Dictionary form is plain. Compare with polite:

Dictionary (Plain)	Masu (Polite)	Meaning
食べる	食べます	eat
行く	行きます	go
する	します	do
来る	来ます	come
飲む	飲みます	drink

Important: Plain ≠ rude. Context matters!

Present/Future Tense

Dictionary form expresses both present and future:

毎日本を読む
"I read books every day" (present habitual)

明日本を読む
"I'll read a book tomorrow" (future)

Context determines which meaning.

Common Conversation Patterns

Making Suggestions

一緒に行く？
"Want to go together?"

これ食べる？
"Want to eat this?"

Stating Intentions

今日は早く帰る
"I'm going home early today"

明日勉強する
"I'll study tomorrow"

Asking About Plans

週末何する？
"What will you do this weekend?"

どこ行く？
"Where are you going?"

Grammar Patterns Using Dictionary Form

と思う (to think)

明日雨が降ると思う
"I think it will rain tomorrow"

彼は来ないと思う
"I think he won't come"

つもりだ (intend to)

日本に行くつもりだ
"I intend to go to Japan"

明日勉強するつもりだ
"I intend to study tomorrow"

ことができる (can/able to)

泳ぐことができる
"I can swim"

日本語を話すことができる
"I can speak Japanese"

前に (before)

食べる前に手を洗う
"Wash hands before eating"

寝る前に本を読む
"Read a book before sleeping"

時 (when/time)

日本に行く時
"When I go to Japan"

食べる時
"When eating / Time to eat"

な (prohibition)

ここで遊ぶな
"Don't play here"

それを食べるな
"Don't eat that"

Modifying Nouns

Dictionary form can modify nouns directly:

読む本 - book to read
食べる物 - thing to eat
行く場所 - place to go
住む所 - place to live

With の

泳ぐのが好き
"I like swimming"

料理するのは楽しい
"Cooking is fun"

Negative Dictionary Form (ない-form)

Dictionary form has a negative counterpart:

食べる → 食べない (don't eat)
行く → 行かない (don't go)
する → しない (don't do)
来る → 来ない (don't come)

Question Sentences

Add か or use rising intonation:

明日来る？
"Are you coming tomorrow?"

これ食べる？
"Will you eat this?"

日本語分かる？
"Do you understand Japanese?"

Formal Writing

Dictionary form appears in:

- Newspaper headlines
- Academic writing
- Technical manuals
- Signs and notices

Example:

本日休業する
"Closed today" (sign)

Common Mistakes

Mistake 1: Using Plain Form in Formal Situations

Wrong: 先生、明日行く ❌
Right: 先生、明日行きます ✓

Wrong: これ食べる？ (to boss) ❌
Right: これを食べますか？ ✓

Use polite forms with superiors!

Mistake 2: Confusing with Polite Form

Dictionary: 食べる (casual)
Polite: 食べます (formal)

Don't mix: 食べるます ❌

Mistake 3: Wrong Conjugation Base

Wrong: Using dictionary form where te-form needed
食べる + ください → 食べてください ✓
(Not: 食べるください ❌)

Recognizing Dictionary Form

Godan Verbs

All end in -u sound
買う, 書く, 読む, etc.

Ichidan Verbs

End in -eru or -iru
食べる, 見る, 起きる, etc.

Irregular

する, 来る

When NOT to Use

With ください

Wrong: 食べるください ❌
Right: 食べてください ✓

With いる/ある (present progressive)

Wrong: 食べるいる ❌
Right: 食べている ✓

With た (past tense)

Wrong: 食べるた ❌
Right: 食べた ✓

Practice Sentences

Casual Conversation

今日何する？
"What are you doing today?"

一緒に映画見る？
"Want to watch a movie together?"

明日は休む
"I'm taking tomorrow off"

With Grammar Patterns

日本語を勉強することが好きだ
"I like studying Japanese"

彼は来ると言った
"He said he would come"

食べる前に祈る
"Pray before eating"

Key Takeaways

✓ Dictionary form = basic, unconjugated verb
✓ Used in casual speech and grammar patterns
✓ NOT rude, but inappropriate in formal situations
✓ Expresses both present and future
✓ Required for many grammar constructions
✓ Can modify nouns directly
✓ Found in dictionaries (hence the name)

Master dictionary form - it's the foundation for all other conjugations!

Next: Masu Form (Polite Present)

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