usage - 希望 expressing verbs

This time I have problem with a grammar point. It's the use of these expressions:

したい

してほしい、してもらいたい、していただきたい

させたい

させてほしい、させてもらいたい、させていただきたい

My problem comes from the questions the excercise asks me, that are:

誰の希望? and するのはだれ? for each of the verb forms. The anwers, obviously, are 私 and 相手, but don't know in which case the verbs refer to "me" or the "other".

I've recognized that in the last two expressions the verb is in causative form, but this use with -もらう is not so clear to me.

So, I'd like to know when I have to use and how to translate (especially the last two) all these expressions I mentioned above.

Please, help.

Answer

したい -> I want to do something. Normal form to express what you want to do.

してほしい、してもらいたい、していただきたい -> I want someone to do something (for me). This is used often when you are requesting for help/ favor. The result of the action is usually very important to the requester.

させたい -> I want (to cause) someone to do something. This is when you know you have power over someone to do something and it usually focus on that action process (the result of the action usually does not matter).

させてほしい、させてもらいたい、させていただきたい -> I want someone to cause me to do something --> Let me do something (for you). This is often used when you are offering help/ service to other people.

EDIT

Examples are:

• したい: ケーキを食べたい。--> I want to eat a cake.


• してほしい：明日の打ち合わせのため、A4サイズノートを持ってきてほしい。 --> For tomorrow's meeting, please bring A4 sized note.


• させたい：弟は病気なので、健康的な食べ物を食べさせたい。 --> My brother is sick, so I want him to eat healthy food.


• させていただきたい：その件に関して詳しいので、解決させていただきたい。　--> I am familiar with that matter, so please let me solve it.