Difference between passive voice and causative-passive form


I am confused with following question. What's the difference between たべられる and
たべさせられる?




  * 食べる "to eat (something)" _(active voice)_

  * 食べられる "to be eaten (by someone)" _(passive voice)_

  * 食べさせる "to make/let (someone) eat (something)" _(active voice, causative)_

As you might know, the passive voice can sometimes express a feeling of
unhappiness towards the result of the action (that is done against one's
will).

In this case, the one doing the action of the verb is always doing it against
his will, forced by someone.

Hence, 食べさせられる means "to be forced (by someone) to eat (something)".

> 私はケーキを **食べた** 。  
>  I ate the cake.
>
> ケーキは私に **食べられた** 。  
>  The cake has been eaten by me. ← _Unnatural because of the inanimate
> subject_
>
> 私は弟にケーキを **食べさせた** 。  
>  I made/let my little brother eat the cake.
>
> 私は兄にケーキを **食べさせられた** 。  
>  My big brother made me eat the cake. / I've been forced by my big brother
> to eat the cake.
>
> 私は友達に一時間も **待たせられた** 。  
>  I had to wait my friend for a good hour. / My friend made me wait a good
> hour.

For the Godan verbs, される is often used instead of せられる:

> 待つ → 待たせられる → 待た **される**




  * 食べる "to eat (something)" _(active voice)_

  * 食べられる "to be eaten (by someone)" _(passive voice)_

  * 食べさせる "to make/let (someone) eat (something)" _(active voice, causative)_

As you might know, the passive voice can sometimes express a feeling of
unhappiness towards the result of the action (that is done against one's
will).

In this case, the one doing the action of the verb is always doing it against
his will, forced by someone.

Hence, 食べさせられる means "to be forced (by someone) to eat (something)".

> 私はケーキを **食べた** 。  
>  I ate the cake.
>
> ケーキは私に **食べられた** 。  
>  The cake has been eaten by me. ← _Unnatural because of the inanimate
> subject_
>
> 私は弟にケーキを **食べさせた** 。  
>  I made/let my little brother eat the cake.
>
> 私は兄にケーキを **食べさせられた** 。  
>  My big brother made me eat the cake. / I've been forced by my big brother
> to eat the cake.
>
> 私は友達に一時間も **待たせられた** 。  
>  I had to wait my friend for a good hour. / My friend made me wait a good
> hour.

For the Godan verbs, される is often used instead of せられる:

> 待つ → 待たせられる → 待た **される**

