How Japanese Verbs Work | Katsuyō Academy

Why Conjugation Matters

In Japanese, verbs change their form to express time (past/present), politeness, negation, desire, ability, and more. Unlike English where we add helper words ("I will go", "I can go"), Japanese transforms the verb itself.

Example:

食べる (taberu) = to eat
食べない (tabenai) = don't eat
食べます (tabemasu) = eat (polite)
食べた (tabeta) = ate
食べたい (tabetai) = want to eat

The Three Verb Types

Every Japanese verb falls into one of three categories. Understanding which type you're working with is the first step.

五段 Godan

"Five-step" verbs that conjugate by shifting through 5 vowel rows

Examples:
行く、話す、飲む

一段 Ichidan

"One-step" verbs with a stem that never changes

Examples:
食べる、見る、寝る

する Suru

Irregular verbs formed by adding する to nouns

Examples:
する、勉強する、料理する

How to Identify Verb Types

Step 1: Does it end in する?

✓

YES → It's a Suru verb

Examples: する、勉強する、散歩する

→

NO → Continue to Step 2

Step 2: Does it end in -eru (える) or -iru (いる)?

✓

YES → Probably Ichidan

Examples: 食べる (taberu), 見る (miru), 起きる (okiru)

⚠️ Watch Out for Exceptions!

Some verbs look like ichidan but are actually godan:
走る (hashiru) - to run [GODAN]
帰る (kaeru) - to return [GODAN]
知る (shiru) - to know [GODAN]

Step 3: Everything else

✓

It's Godan

Ends in: く、ぐ、す、つ、ぬ、ぶ、む、る、う
Examples: 行く (iku), 話す (hanasu), 飲む (nomu), 買う (kau)

Foundation: The Hiragana Sound System

Japanese sounds are organized in rows and columns. Godan verbs work by shifting between these rows:

Row	k-	s-	t-	m-	r-	w-
あ (A)	か	さ	た	ま	ら	わ
い (I)	き	し	ち	み	り	い
う (U)	く	す	つ	む	る	う
え (E)	け	せ	て	め	れ	え
お (O)	こ	そ	と	も	ろ	お

💡 Key Insight:

Notice how each column keeps the same consonant sound (k-, s-, t-, etc.), but the vowel changes (a, i, u, e, o). When we conjugate godan verbs, we're moving up and down these columns to create different forms.

Godan Verbs: The Five-Row System

Godan verbs work by changing the final sound to a different row. Let's use 話す (hanasu - to speak) as our example:

Watch the Transformation

NEGATIVE (あ)

話さない

hanasanai

ます-STEM (い)

話します

hanashimasu

DICTIONARY (う)

話す

hanasu

POTENTIAL (え)

話せる

hanaseru

VOLITIONAL (お)

話そう

hanasou

Step-by-Step Process

1. Start with the dictionary form: 話す (hanasu)

2. Identify the final sound: す (su) - this is in the う-row

3. Find it in the chart: Look in the s-column, う-row = す

4. To make negative: Move to the あ-row in the same column: す → さ

5. Add the ending: はなさ + ない = 話さない

⚠️ Past Tense: Special Sound Changes

Past tense is the one exception to the row-shift pattern. Instead, godan verbs use special endings based on the final sound:

く → いた
書く → 書いた

ぐ → いだ
泳ぐ → 泳いだ

す → した
話す → 話した

つ/る/う → った
買う → 買った

む/ぶ/ぬ → んだ
飲む → 飲んだ

Ichidan Verbs: The Simple Pattern

Ichidan verbs are called "one-step" because the stem never changes. You simply drop る and add endings.

The Formula

Stem + る → Stem + ending

Example: 食べる (taberu - to eat)

Form	Process	Result
Negative	たべ + ない	食べない
Polite	たべ + ます	食べます
Past	たべ + た	食べた
Want to	たべ + たい	食べたい
Potential	たべ + られる	食べられる
Volitional	たべ + よう	食べよう

💡 Why It's Easy:

With ichidan verbs, once you memorize the endings (ない, ます, た, たい, られる, よう), you can conjugate any ichidan verb. No row-shifting, no special rules, no exceptions!

Suru Verbs: The Irregular Pattern

Suru verbs are formed by adding する to a noun. They're irregular, but once you learn how する conjugates, you can apply it to all suru verbs.

Example: 勉強する (benkyou suru - to study)

Form	する becomes...	Result
Negative	しない	勉強しない
Polite	します	勉強します
Past	した	勉強した
Want to	したい	勉強したい
Potential	できる	勉強できる
Volitional	しよう	勉強しよう

💡 Special Note:

Notice that the potential form uses できる instead of following the regular pattern. This is why suru verbs are considered "irregular" - they have their own special rules!

Putting It All Together

Now that you understand the patterns, here's your strategy for success:

1️⃣

Identify the Type

First, figure out if your verb is godan, ichidan, or suru

2️⃣

Apply the Pattern

Use the right conjugation method for that verb type

3️⃣

Practice, Practice!

Use The Conjugator to drill until it becomes automatic