Purpose

This page will explain two ways to explain the purpose of an action, ために and ように

ために

Reason For
Dictionary form Verb + ために
Noun + のために

ために indicates the reason for an action or event.

Reason

ために may be used purely to give a cause. Unlike せい or おかげ, ため is neutral.

• 雨のために遅れた
  I was late because of the rain.
  
  
• 心配のために疲れた
  I’m tired from all the worrying.
  
  
• 事故のために電車が遅れた
  The train was late because of an accident.
  
  
• 勉強していたため、パーティに行けなかった
  I couldn’t go to the party because I was studying.

*に may be omitted/replaced with a comma with this usage.

Purpose

Because ために describes a reason, it may also be used to indicate the purpose of an action.
This pattern is commonly used with people.
This meaning has a positive nuance; sort of like “wanted to do for“.

• 彼のために片づけた
  I clean up for him.
  
  
• 勉強するために本を借りた
  I borrow a book so I could study.
  
  
• 日本に行くために貯金している
  I am saving money so that I can go to Japan. 
  
  
• 食べるために必死だ
  Desperately doing stuff in order to eat.
  
  
• Hakushiki Japaneseのために寄付をした
  I donated for Hakushiki Japanese.
  
  

ように

Act such that…/Act so that
Present/Future Tense verb + ように
Plain Negative Verb + ように

ように can also used to describe purpose, however it describes “how” you will act to achieve a goal.

I say “how” because ように is an adverb and modifies a verb (how the verb is done).
This means it can be used for to describe purpose and as an adverb (as if)

This pattern frequently uses potential form, passive form, and なる before ように
For a purpose meaning, it will generally not use dictionary form verbs. (See below)

Purpose Examples

• 明日頑張られるようにしっかり寝て
  Rest up so you can try tomorrow. (Rest with goal in mind)
  
  
• 勉強ができるように、本を借りた
  I borrow a book so I would be able to study.
  
  
• 殺さされないように気を付けて
  Be careful so that you aren’t killed.
  
  
• 起こさないように静かに歩いて
  Walk quietly so we don’t’ wake up people.
  
  
• お金持ちになるように頑張る
  Try hard to become a rich person
  
  

Adverb Examples

• 食べるようにした
  Did as if to eat.
  
  
• 飲むように見せかけた
  Made it look like he drank.
  
  
• 勉強するように本をよんだ
  Read a book as if studying it.
  
  
• 残業を毎日するようになった
  It became that we do overtime everyday

ますように

Although typically only plain form verbs go in front of ように, ますように may be used.
However it is a special case as it is primarily used for hope/prayer type statements. It usually appears at the end of a sentence.

• 明日が素敵な一日になりますように(祈っています）
  I hope that tomorrow becomes a wonderful day. 

Comparison

• 勉強するために本を借りた
  Borrowed a book for studying.
   
• 勉強するように本を借りた X 
  Borrow so that you study. X する should be できる
  
  
• 勉強ができるように本を借りた
  Borrow so that you can study → I borrowed a book to be able to study.