しよう meaning of this word?


> タイ語の手紙を翻訳するボランティアをしようと思ってるんです.

this is from a conversation between 2 people. one asked the other "what are
you reading " and the other person said I study thailand language and the
reason is タイ語の手紙を翻訳するボランティアをしようと思ってるんです.

here しよう means what ? and is it a rule in grammar or just a word ?




> タイ語の手紙を翻訳するボランティアをしようと思ってるんです。  
>  (Because) I am thinking of doing volunteer work to translate letters in
> Thai.

しよう is the (non-polite) volitional form of the verb する ("to do").

  * [Desire and Volition](http://www.guidetojapanese.org/learn/complete/desire_volition)
  * [The Japanese volitional form (～しよう、～しましょう): much more than just “Let's”](http://selftaughtjapanese.com/2015/02/17/the-japanese-volitional-form-%E3%81%97%E3%82%88%E3%81%86%E3%80%81%E3%80%9C%E3%81%97%E3%81%BE%E3%81%97%E3%82%87%E3%81%86-more-than-just-lets/)

ボランティアをする is "do volunteer work", "to participate in charity activities".
While _volunteer_ is a verb in English, ボランティア is just a noun in Japanese and
you have to use を + する.




> タイ語の手紙を翻訳するボランティアをしようと思ってるんです。  
>  (Because) I am thinking of doing volunteer work to translate letters in
> Thai.

しよう is the (non-polite) volitional form of the verb する ("to do").

  * [Desire and Volition](http://www.guidetojapanese.org/learn/complete/desire_volition)
  * [The Japanese volitional form (～しよう、～しましょう): much more than just “Let's”](http://selftaughtjapanese.com/2015/02/17/the-japanese-volitional-form-%E3%81%97%E3%82%88%E3%81%86%E3%80%81%E3%80%9C%E3%81%97%E3%81%BE%E3%81%97%E3%82%87%E3%81%86-more-than-just-lets/)

ボランティアをする is "do volunteer work", "to participate in charity activities".
While _volunteer_ is a verb in English, ボランティア is just a noun in Japanese and
you have to use を + する.

