「じ・ず」 vs 「ぢ・づ」

 Pronunciation (Modern Japanese)

• じ = ぢ → ji

• ず = づ → zu
  →They sound exactly the same.

Rule #1 (Most Important)

Use 「じ」 and 「ず」 by default

Examples:

• せかいじゅう sekaijuu（世界中）all over the world

• ちず  chizu（地図）map

• じつづき jitsuzuki（地続き）adjointing

＊ If unsure → じ / ず is almost always correct

When to Use 「ぢ」 or 「づ」

① Repeated Sounds (Same Root Sound)

If a word has ち or つ and the sound repeats:

Original	Result	Example
ち → ぢ	ちぢむ	縮む  to shrink
ち → ぢ	ちぢれる	縮れる to curl
つ → づ	つづく	続く to continue
つ → づ	つづら	(Japanese wicker basket)
つ → づ	つづみ	(Japanese hand drum)

＊ Memory tip:
ち repeats → ぢ
つ repeats → づ

② Compound Words (Rendaku)

When two words join, and the second word voices:

Parts	Word	Meaning
はな + ち	はなぢ	nosebleed
みっか + つき	みかづき	crescent moon
いろ + つく	いろづく	to gain colour

Still Not Sure?

＊ Choose 「じ」 or 「ず」
✔ Modern Japanese prefers them
✔ Rarely causes problems

Ultra-Short Summary

• Default → じ / ず

• Repetition → ち→ぢ / つ→づ

• Compounds → sometimes ぢ / づ

• Doubt? → じ / ず