Understanding the subject and object when using 満足/満足できない

Question

I'm a little confused as to who the sentence is referring to as the satisfied/dissatisfied person.

for example: 彼はもう彼女満足できない。

I understand this　sentence to mean: He cant be satisfied by/with her anymore.

I know I can flip 彼 and 彼女 to mean that the girl is the one unsatisfied with him. But this would make her the subject.

How would I structure a sentence in Japanese that would still keep him as the subject?

for example: He cant satisfy her anymore.(it's what I originally thought the example meant)

Also, is there a rule I should follow in the future to understand it correctly?

Answer 1

To say "He can't be satisfied by/with her anymore", you use the particle に, as in:

「彼はもう彼女に満足できない。」

To say "He can't satisfy her anymore", you'd say:

「彼はもう彼女を満足させられない。」

using the causative form ～させる. (られる is the potential auxiliary.)

Basic structures are:

「AがBに満足する」 -- "A is satisfied with B"
「AがBを満足させる」 -- "A satisfies B"