【English】
Here you can translate 28 languages. Translation accuracy is about 75%.
If you wish to translate, please say the language you wish to translate into.

【日本語】
ここでは、28の言語を翻訳することができます。翻訳精度は約75％です。
翻訳を希望する場合は、翻訳したい言語を言ってください。

【Italienisch】
Qui è possibile tradurre 28 lingue. L'accuratezza della traduzione è di circa il 75%.
Se si vuole tradurre, basta dire la lingua in cui si vuole tradurre.

【Deutsch】
Hier können 28 Sprachen übersetzt werden. Die Übersetzungsgenauigkeit liegt bei etwa 75 %.
Wenn Sie eine Übersetzung wünschen, geben Sie die Sprache an, in die Sie übersetzen möchten.

【中文】
在这里，可以翻译28种语言。 翻译准确率约为75%。
如果你想翻译，只要说你想翻译成的语言。

It seems to me that you need to read the guide of the Translating Scratch forum here as well as this Japanese forum. I quote the first sentence.

apple502j wrote:

This forum is intended for use by Scratch translators, who translate Scratch Editor and Website into many languages. Please don't discuss about Translate Extension or request project translation. For requests on translation for things you make (like projects, studio descriptions, etc) Requests forum will do.

These topics are welcome:

• Topics that are used to communicate between translators.
  
• Topics that shows how to help us translate Scratch.
  
• Topics about International Scratch-Wiki.
  

Please keep these promises