て form of causation form when used with もらう/くれる


I previously asked a question regarding causative form of verb ([Using もらう
with に/を particle and passive/causative
forms](https://japanese.stackexchange.com/questions/68173/using-%E3%82%82%E3%82%89%E3%81%86-with-%E3%81%AB-%E3%82%92-particle-
and-passive-causative-forms/68176#68176))

Looking at example sentence 5 (AさんはBさんに病院に送らせてもらう), this translates to "B
let/made (someone/A) send (something else/ someone else) to hospital (as a
favor for A)", or at least is what I wrote, and it seems from the answer that
this translation is indeed correct.

Upon reading further on japanese causative forms, I stumbled upon
<https://www.wasabi-jpn.com/japanese-grammar/japanese-grammar-proper-
particles-with-the-causative-form/> which states that the action taker is
marked with the に particle (or sometimes を). Assuming that's the case,
wouldn't the sentence translate to "A let B send (someone/A) to
hospital"(normally used as first person), where the てもらう/てくれる only serves as a
more explicit marker that A "let" instead of "made" B.

What went wrong with my understanding here. Any pointers would be appreciated.




It bears repeating that this sentence is artificial in that you would normally
not twist the sentence that much, and you would use a sentence with 許可 or
something to denote the fact that B-san gave permission for the action. And I
didn't notice to mention this previously, but since てもらう is present tense,
"let/made" should really be "lets/makes" (present) or "will let/will make"
(future) here.

送らせる ("to make (sb) send (smt)"/"to let (sb) take (smt) (somewhere)") here is
treated as the full verb, so it will never have the simpler meaning of 送る ("to
send"/"to take (sb)(somewhere)") as long as it is used in that form. And since
に points to the action taker in a passive sentence, here, B-san is the one who
does the direct action 送らせる, while the もらう is the "action" (of receiving a
favor) taken by the passive party, which is almost certainly (but not
necessarily) A-san as given by the は. (You could also interpret this sentence
to have another passive recipient of B-san's 送らせる and have A-san be related to
this in some other way, like "I (C-san) will have B-san let me take A-san to
the hospital", but this would make the meaning/usage of the sentence even more
unnatural than it already is.)

てもらう and てくれる would be opposite in meaning here. AさんはBさんに病院に送らせてくれる would also
sound really weird, but it would technically translate to something like
"A-san will let/make B-san take (someone, probably the speaker?) to the
hospital, and this is considered a good thing by the speaker (who is probably
neither A-san nor B-san))". Here I'd assume A-san is B-san's superior and
decided to do a favor to the speaker by ordering B-san to take the speaker to
the hospital.




It bears repeating that this sentence is artificial in that you would normally
not twist the sentence that much, and you would use a sentence with 許可 or
something to denote the fact that B-san gave permission for the action. And I
didn't notice to mention this previously, but since てもらう is present tense,
"let/made" should really be "lets/makes" (present) or "will let/will make"
(future) here.

送らせる ("to make (sb) send (smt)"/"to let (sb) take (smt) (somewhere)") here is
treated as the full verb, so it will never have the simpler meaning of 送る ("to
send"/"to take (sb)(somewhere)") as long as it is used in that form. And since
に points to the action taker in a passive sentence, here, B-san is the one who
does the direct action 送らせる, while the もらう is the "action" (of receiving a
favor) taken by the passive party, which is almost certainly (but not
necessarily) A-san as given by the は. (You could also interpret this sentence
to have another passive recipient of B-san's 送らせる and have A-san be related to
this in some other way, like "I (C-san) will have B-san let me take A-san to
the hospital", but this would make the meaning/usage of the sentence even more
unnatural than it already is.)

てもらう and てくれる would be opposite in meaning here. AさんはBさんに病院に送らせてくれる would also
sound really weird, but it would technically translate to something like
"A-san will let/make B-san take (someone, probably the speaker?) to the
hospital, and this is considered a good thing by the speaker (who is probably
neither A-san nor B-san))". Here I'd assume A-san is B-san's superior and
decided to do a favor to the speaker by ordering B-san to take the speaker to
the hospital.

