Dative subject constructions with 「もらえませんか」


Back to basics. I have heard sentences similar to these ones online that
attest the same structure

>
> 私も弾いてみたい、と思った私はすぐさま「私にも教えてもらえませんか。」と願い出ました。([source](http://www.tetsukuro.net/tetsukoma.php))

>
> あとで時間があったら、その秘訣を私にも教えてもらえませんか。([source](https://wikiwiki.jp/azphel/%E3%82%B2%E3%83%AB%E3%82%AF%E3%83%9E%E3%83%AB%E3%82%B9%E8%A6%81%E5%A1%9E2))

>
> アーモンドさん（左）「私に貸してもらえませんか？」([source](https://ameblo.jp/snakewood/entry-12557438011.html))

>
> 是非とも夢ある皆さんの力を私に貸してもらえませんか？([source](https://www.a-i-s.co.jp/files/news43.html))

Why に? In all of these sentences isn't the subject 「私」? The agent of the
action is the other party, and 「もらう」determines the subject is the benefector
of the action. What am I missing here? There seems to be a function fusion of
indirect object with subject of sentence.




As noted in the comments by Leebo, Eddie Kal, and A. Ellett, the に marks the
agent of actions in certain constructions. We sometimes use _by_ in English in
a similar fashion.

In the ～てもらう construction, consider that the agent of the verb もらう is
_getting_ (もらう) something _done_ (the ～て verb) for them. This is, in some
ways, not far from the passive, where に is also used to mark the agent (the
doer of the action) and は or が to mark the patient (the receiver of the
action).

  * Passive: 
    * 私 **[は]{●}** 先生 **[に]{●}** 教え **[ら]{●}[れ]{●}[た]{●}**
  * "Getting": 
    * 私 **[は]{●}** 先生 **[に]{●}** 教え **[て]{●}[も]{●}[ら]{●}[っ]{●}[た]{●}**

We might express this in English as:

  * Passive: 
    * I **was** taught **by** the teacher
  * "Getting": 
    * I **got** taught **by** the teacher

_Note: In English, the two are so close that they are essentially fusing in
modern colloquial usage. The "getting" sense of "receiving" is thus often
expressed in a slightly wordier fashion, to avoid ambiguity:_

  * _" Getting" with explicit "receiving":_
    * _I **got** the teacher **to teach me**_

The key point to remember for ～てもらう constructions is that they are similar to
the passive, and the agent (doer) of the ～て verb generally takes に.

