What's the difference between 話せる and 話す?


I came across [話]{はな}せます in the [Japanese WOTD chat
room](http://chat.stackexchange.com/transcript/message/4891082#4891082).

[code]

    あなたは英語が話せますか？ Can you speak English?
    
[/code]

What's the difference between it and [話]{はな}します?

(Googling got some hits, but they were from user generated content, which
isn't always [reliable](https://japanese.meta.stackexchange.com/a/804/91))




話せる is the potential form of 話す. The potential form implies being able to do
the verb. It's an immensely useful form!

The potential form is created by adding られる to the stem of る-verbs, or adding
the え form of the final kana of う verbs plus る to the stem of う verbs (I think
the cool kids call those ichidan and godan verbs, respectively).

> 食べる - to eat  
>  食べられる - to be able to eat
>
> [泳]{およ}ぐ - to swim  
>  泳げる - to be able to swim
>
> この[漢字]{かんじ}が[読]{よ}めますか。 - Can you read this kanji?  
>  はしが使えますか。 - Can you use chopsticks?

A special exception: Just use できる for する-type verbs.

> 車が[運転]{うんてん}できますか。 - Can you drive a car?




話せる is the potential form of 話す. The potential form implies being able to do
the verb. It's an immensely useful form!

The potential form is created by adding られる to the stem of る-verbs, or adding
the え form of the final kana of う verbs plus る to the stem of う verbs (I think
the cool kids call those ichidan and godan verbs, respectively).

> 食べる - to eat  
>  食べられる - to be able to eat
>
> [泳]{およ}ぐ - to swim  
>  泳げる - to be able to swim
>
> この[漢字]{かんじ}が[読]{よ}めますか。 - Can you read this kanji?  
>  はしが使えますか。 - Can you use chopsticks?

A special exception: Just use できる for する-type verbs.

> 車が[運転]{うんてん}できますか。 - Can you drive a car?

