もらえる, 見える rules


From what I learned,

> もらえる = もらうことが出来る  
>  'can be got'
>
> 見える = 見ることが出来る  
>  'can be seen'

This looks like there is some kind of a more general rule for this
transformation.

  1. If there is a pair of such verbs, is the one with ~え~ always meaning ~ことが出来る?
  2. Is there any rule when can I create a ~え~ verb this way?




They are some ways to get verbs end with える:

  1. 五段動詞 can change the last kana to え段 and add る to form a kind of 可能動詞, like:

> もらう → もらえる  
>  書く → 書ける  
>  飛ぶ → 飛べる

They have a similar meaning of the "れる" form : もらわれる 書かれる 飛ばれる. In modern
Japanese, the れる form is not so popular as the form of "可能動詞".

  2. える is a verb that can be used after the 連用形 of other verbs to show ability or possibility:

> ある → ありえる  
>  起こる → 起こりえる

みえる and 聞こえる (I don't know if there are more) are another story, they are from
みゆ and きこゆ in classic Japanese.




No to both of your questions. You are mixing up different things.

  * `もらえる` is the potential form of the verb `もらう`, and it means the same thing as `もらうことができる`.

  * `見える` 'can be seen, is observable' is related to the verb `見る` 'see', but means a different thing. The construction is different from `見ることができる`.

