やる and あげる when used with て-form of verb


What's the difference when using やる and あげる with the て-form of a verb. For
example: 教えてやる and 教えてあげる.




The difference is that やる is only used with animals or very, very young
children, as it sounds very patronising, as though the person you are doing a
favor to is way lower than your level socially speaking. So basically, if you
~てやる someone, you are treating them like an animal (bad idea).

Take into account that even あげる itself can sound patronising, so it should be
used only with people at the same social level than you (e. g. a friend) or
lower (e. g. one of your employees).

For example:

> 太郎【たろう】くんにギターを弾くのを **教えてあげた** 。 I taught Tarou to play the guitar.
>
> 私の犬にちゃんと座【すわ】るのを **教えてやった** 。I taught my dog to sit properly.

Grammatically, they convey the same idea: to perform an action in someone's
favor or for the sake of someone.

