てもらう

もらう with an object reports a transfer and nothing more. 〜てもらう marks an invited favour, unasked kindness takes 〜てくれた instead.

てもらう treats it as a favor you welcomed (直なおしてもらった). られる treats it as something merely done to you (勝手かってに直なおされた).

させる grants the act, from the person allowing it (使つかわせる). てもらう receives a favor, from the person benefiting (直なおしてもらう).

てもらう receives a favor someone else does for you (直なおしてもらった). させてもらう receives permission to do it yourself instead (直なおさせてもらった).

貸かしてあげた puts the giver's kindness front and center, and can sound like bragging. 貸かしてもらった puts the receiver first, and usually suggests the favor was asked for.

手伝てつだってほしい states the wish and stops there, nothing has happened yet. 手伝てつだってもらう reports the act as already received, unlike the still-pending wish.

てもらう is the neutral, everyday choice for the same favor. ていただく elevates the giver, standard toward teachers and superiors, odd toward your child.

友達ともだちが教おしえてくれた makes the giver the subject, showing spontaneous kindness. 友達ともだちに教おしえてもらった makes the receiver the subject, hinting they asked.

Plain thanks are built on くれて, the natural everyday form. もらう only reaches thanks through humble いただき, in formal speech.

てもらった reports a favor already received, a finished event (昨日きのう直なおしてもらった). てもらいたい reports nothing yet, so any time word is a deadline (明日あすまでに直なおしてもらいたい).