V て-form + おきます (V-te okimasu) — Do it in advance / leave it as it is

Getting it done now for later, or leaving it just as it is.

Formula (सूत्र ढाँचा)

Verb N + を + Vて + おきます

「〜ておきます」has two meanings.
First — doing it in advance. Something is coming later, so you do it now: 旅行の前に切符を買っておきます (I buy the ticket before the trip).
Second — leaving it as it is. You do not change the state, you let it stay: 暑いですから、窓を開けておいてください (it is hot, so please leave the window open).
The sentence tells you which meaning it is — a time word like 〜の前に or 明日 points to preparation.

The particle stays を, because this is an action you do — it does not become が the way てあります does.
In speech it shortens: 〜ておく → 〜とく, 〜でおく → 〜どく: 買っとく, 読んどく.
When you write, use the full form.

旅行の前に切符を買っておきます。

りょこうのまえにきっぷをかっておきます。

I will buy the ticket before the trip.

ここに名前を書いておいてください。

ここになまえをかいておいてください。

Please write your name here beforehand.

暑いですから、窓を開けておいてください。

あついですから、まどをあけておいてください。

It is hot, so please leave the window open.

Question: 1/3

Which says that you will buy the ticket in advance, before the trip?

💡 Hint: Which form means doing now what you will need later?