Ja/Ju/Jo Two forms?

[bloritsch]

In studying the hiragana and katakana charts, I noticed that there are two sets of combinations that are pronounced the same: ja, ju, jo

I couldn't hear any difference between them in all six of the speakers on the charts here at JPod 101. What are some examples of words that use these different forms?

じゃ　じゅ　じょ
ぢゃ　ぢゅ　ぢょ

How are they different (other than spelling)? Obviously I need to learn them and recognize them when I see them, but I'd like a little more insight on them.

[QuackingShoe]

They're effectively the same, but not interchangeable. More to the point, the じ　and ぢ are, whether or not they're followed by ゅ etc. The short rule is basically "only use じ unless we say otherwise." The long rule is http://en.wikipedia.org/wiki/Hiragana#Spelling_rules

[hatch_jp]

ぢゃ, ぢゅ or ぢょ is used for jocular use, name of commodity or proper noun.

Only exceptions I know are folloing word:
　茶飲み茶碗（ちゃのみぢゃわん） ： a cup for drinking tea
　抹茶茶碗（まっちゃぢゃわん） ： a cup for drinking green tea
　湯のみ茶碗（ゆのみぢゃわん） ： a cup for dringking hot water
　盆提灯（ぼんぢょうちん） ： Japanese lantern for Bon festival

* I cant explain the difference among ～茶碗 properly.
　　http://www.maikoshop.com/kiyomizu/yunomi01.htm
* Bon festiva : http://en.wikipedia.org/wiki/Bon_Festival

[bloritsch]

Only exceptions I know are folloing word:
　茶飲み茶碗（ちゃのみぢゃわん） ： a cup for drinking tea
　抹茶茶碗（まっちゃぢゃわん） ： a cup for drinking green tea
...

According to Rikaichan, only the first item you listed would be using ju-wa-n (ぢゅわん). The 茶碗 combination by itself had the pronunciation guide of chu-wa-n (ちゅわん). It must be one of those things that change as it becomes a compound. I'm not saying Rikaichan is the ultimate authority, but it is a very 便利 tool while I am learning.

But thank you for some examples of the non-standard way of spelling the sound "ju" in real words. I figured one would be the "blessed way" and the other would be the exception.