遊ぶ: Full 五段 -ぶ Paradigm

This is the reference paradigm for a 五段 (godan) verb ending in -ぶ. The model is 遊ぶ（あそぶ, "to play, to hang out, to have fun"). The defining feature of the -ぶ class is that its te-form and past take the voiced nasal 撥音便 (hatsuon-bin) — 遊んで, 遊んだ — the very same pattern as -む (読む→読んで) and -ぬ (死ぬ→死んで). The one thing you must not do is leave it unvoiced: ×遊んて and ×遊んた are the errors this page exists to kill.

The complete paradigm

The ば-row ladder

Consonant b fixed; the vowel slides across the ば行 column. Notice how tidy this is compared with the -つ verb: ば・び・ぶ・べ・ぼ romanize straight as ba, bi, bu, be, bo, with no spelling surprises.

撥音便: nasal, and the connector voices to で／だ

The te-form 遊んで and the past 遊んだ both replace ぶ with ん, and then the connector voices: て→で, た→だ. Think of it as momentum — the ぶ is already a voiced sound, so the voicing hums straight through the nasal ん and lands on で/だ. You physically can't glide from a buzzing ん into a crisp, unvoiced t, which is exactly why the language voices it.

• 遊ぶ a-so-bu → a-so-n-de → 遊んで
• 呼ぶ (to call) → 呼んで, 選ぶ (to choose) → 選んで, 運ぶ (to carry) → 運んで — the whole -ぶ family behaves identically.

The あ-row family: negative, passive, causative

Everything negative-flavoured is built on the あ-row 遊ば. The polite 遊びます tempts you to treat び as "the stem," but the negative is 遊ばない (not ×遊びない), the passive 遊ばれる, and the causative 遊ばせる.

The passive 遊ばれる also has a pointed colloquial sense — "to be toyed with," especially romantically. Context and animacy tell the two apart.

The え-row and volitional in use

The potential 遊べる ("can play/hang out"), conditional 遊べば, and plain imperative 遊べ all share the え-row stem; the volitional 遊ぼう is the お-row.

The plain imperative 遊べ and prohibitive 遊ぶな are both blunt; between friends or from an older person they read as warm ribbing, but they are not polite requests. For that you'd use 遊んでください or an invitation like 遊びませんか.

A note on meaning: 遊ぶ is wider than "play"

Before the pitfalls, a semantic caution that saves learners from sounding childish. 遊ぶ does mean a child's "play," but for adults it more often means "to hang out, to go out and have fun, to spend leisure time" — meeting friends, going to a bar, taking a trip. So 週末に友達と遊ぶ is what an adult says about a normal social weekend, not "I play with my friends." It also stretches to "to be idle" (a machine sitting unused: 機械が遊んでいる) and, in the passive we saw, "to be toyed with." Because the meaning is this broad, the derived forms all get real use — which is more than can be said for the previous page's 死ぬ.

How this differs from English

English keeps "play" fixed and adds separate words for everything around it — play, played, is playing, let them play, was made to play. 遊ぶ instead reshapes its own ending: the ぶ becomes ん inside 遊んで, so the connector isn't a separate "and" but part of the verb, and it drags the voicing along with it (で, not て). English has nothing that changes a conjunction's sound to match the verb in front of it; the closest instinct — sloppy "hafta" for "have to" — is just fast speech, whereas 遊んで is the correct written form. Treat the voicing as spelling, not slang.

Common mistakes

Key takeaways

• 遊ぶ is the model 五段 -ぶ verb. Consonant b fixed; the vowel walks ば・び・ぶ・べ・ぼ.
• Te-form and past take the voiced nasal 撥音便: 遊んで, 遊んだ — identical in shape to 読む and 死ぬ.
• The connector voices to で/だ because ぶ is voiced — ×遊んて／×遊んた is the one error to guard against.
• The negative, passive, and causative sit on the あ-row 遊ば; び appears only before ます and 〜たい.
• Compare the identical nasal pattern on 読む and see the whole map on the te/ta sound-change chart.