Remember back in N5 when we talked about how to say "I want to [whatever]."

Specifically, we had sentences like:

トム・クルーズと結婚したいです。
トム・クルーズ　と　けっこん　したい　です。
I want to marry Tom Cruise.
Literally: “Tom Cruise + と + marriage + want to do + です.”

～たい works great when we are talking about what we personally want to do.

But what should we say when we want someone else to do something, or when we want something out of our control to happen?

In that case, we would use...

JLPT N3: ～てほしい

First, let's get ほしい out of the way.

欲しい（ほしい // wanted for; wished for; desired）

If you're not familiar with this unique i-adjective, then please go back and read this lesson:

[NDL #378] - JLPT N5: がほしい.

With that out of the way, you're now ready to take on this lesson's grammar point.

Luckily, it's relatively simple:

want X to happen or be done
→ X て + ほしい

For example, let's say that we're coworkers, and I want you to go buy me some AA batteries and some oolong tea.

I could say...

単三電池とウーロン茶を買ってきてほしいのですが。
たんさん　でんち　と　ウーロンちゃ　を　かって　きて　ほしい　のですが。
I was wondering if you would go get me some AA batteries and oolong tea.
Literally: “size AA + battery + と + oolong tea + を + buy (and) + come (and) + wanted (=ほしい) + のですが.”

Now, I could have said this as a direct request, like this:

単三電池とウーロン茶を買ってきて（ください）。
たんさん　でんち　と　ウーロンちゃ　を　かって　きて（ください）。
(Please) go get me some AA batteries and oolong tea.
Literally: “size AA + battery + と + oolong tea + を + buy (and) + come (and) + please.”

As that is a direct request, though, it requires the listener to directly agree to it or refuse it.

By using ～てほしい, we're softening the request. Specifically, we're just stating what we want to happen out loud, and we use the "softener が" (see this lesson) to hint that this is a request.

Luckily, human beings are not entirely useless at communicating with one another, so when you tell someone, "I want you to go get me some tea" or "I was hoping that you would go get me some tea," they understand that it means "Please go get me some tea."

Magic.

Formation:

All we have to do is attach ほしい to forms in the て-form (positive or negative)...

V て ＋ ほしい（です）

V ないで ＋ ほしい（です）

食べてほしい（です）
たべて　ほしい （です）
want [someone] to eat (something)
Literally: "eat (and) + wanted + (です)."

読まないでほしい（です）
よまないで　ほしい （です）
want [someone] to not read (something)
Literally: "not read (and) + wanted + (です)."

(Note that です is used after ほしい in formal sentences. This makes sense because we do this for all i-adjectives at the end of formal sentences.)

An example:

母が先週から入院しています。はやく元気になってほしいです。
はは　が　せんしゅう　から　にゅういん　しています。　はやく　げんき　に　なってほしい　です。
My mother has been in the hospital since last week. I hope she gets better soon.
Literally: “mother + が + last week + from (=から) + hospitalization + is doing. + soon / quickly + healthy / well + に + become (and) + wanted (=ほしい) + です.”

Now let's see how to say that we want something to NOT happen or be done

この手紙はあなたが二十歳になるまで読まないでほしいのです。
この　てがみ　は　あなた　が　はたち　に　なる　まで　よまないでほしい　のです。
I don’t want you to read this letter until you turn twenty years old.
Literally: “this + letter + は + you + が + twenty years old + に + become + until + not read (and) + wanted (=ほしい) + です.”

So we just saw that to say we want something to NOT happen or be done, we can use "V ないで ＋ ほしい."

This is typically used to request that someone not do something. In other words, it's a different way of saying "V ないで ＋ ください."

However, we can also say "V て ＋ ほしくない" to talk about something that we DON'T want to happen or be done.

This version tends to be used when the listener is not the person we want to not do something. That is, it is not a request.

An example might help:

家族にはインスタントラーメンみたいに体に悪いものは食べてほしくない。
かぞく　に　は　インスタントラーメン　みたいに　からだ　に　わるい　もの　は　たべてほしくない。
I don’t want my family members to eat unhealthy food like instant ramen.
Literally: “family + には + instant ramen + like (=みたいに) + body + に + bad + thing + は + eat (and) + not wanted (=ほしくない).”

It may help to change the earlier sentence's translation to "I want you to NOT read..." instead of "I DON'T want you to read..."

この手紙はあなたが二十歳になるまで読まないでほしいのです。
この　てがみ　は　あなた　が　はたち　に　なる　まで　よまないでほしい　のです。
I want you to not read this letter until you turn twenty years old.
Literally: “this + letter + は + you + が + twenty years old + に + become + until + not read (and) + wanted (=ほしい) + です.”

You may want to read through this section a few times. I personally have a very bad habit of using "V て ＋ ほしくない" when I should use "V ないで ＋ ほしい."

What I mean is that I tend to incorrectly use "V て ＋ ほしくない" for requests.

Finally, note that "V ないで + ほしい" can also be used to criticize someone's behavior, as in the following conversation:

A:
カレーにみそ汁は変だよ。
カレー　に　みそしる　は　へん　だ　よ。
Eating curry with miso soup is weird.
Literally: “curry + に + miso soup + は + weird + だよ.”

B:
わたしはそうは思わないから。あなたの考えを押し付けないでほしい。
わたし　は　そう　は　おもわない　から。　あなた　の　かんがえ　を　おしつけないでほしい。
I don’t think so. So I’d like it if you didn’t try to force your opinion on me.
Literally: “I + は + that (=そう) + don’t think + because (=から). + you + の + thinking / opinion + を + don’t press / don’t impose (and) + wanted (=ほしい).”

To me, this seems to match up pretty nicely with "I'd like it if you didn't...", "I wish you wouldn't...", "I'd prefer it if you didn't..." etc. when insinuating that someone should stop doing something.

A word of warning: You MUST master this grammar point. It is extremely useful in everyday life.