Learn Hardcore Japanese: watasi ha yasumi no mae ni sigoto wo hayame ni owarasetai desu. - I want to finish my work early before a day off.

You can sometimes say 休み前に, especially in informal or written styles, and people will understand you.
However, 休みの前に feels more neutral/natural and is the safest for learners.

What exactly does 休み mean here? Is it “vacation”, “holiday”, or “break”?

休み is quite flexible; it just means some kind of time off / rest.

Context decides:

It could be a day off from work.
It could be a holiday period (e.g., New Year’s holiday, Golden Week).
It could be just “my break” (like a coming period of rest).

More specific words:

休日（きゅうじつ） = a day off, a public holiday.
休暇（きゅうか） = vacation/leave (often official: paid leave, etc.).

In everyday speech, 休み is very common and natural.

Why are there two に in the sentence (in 前に and 早めに)? Don’t they conflict?

They do different jobs:

休みの前に – this に marks time: “before the break”.
早めに – this に turns 早め into an adverb: “early / a bit earlier”.

Japanese often has multiple に in one sentence, each with its own role.
There’s no conflict, because each one is attached to a different word/phrase.

What is the difference between 早めに and 早く?

Both relate to “early”, but the nuance is different:

早く終わらせたい
→ “I want to finish early / quickly.”
Neutral “early”; often just “not late”.
早めに終わらせたい
→ “I want to finish a bit earlier than usual / earlier than needed.”
早め has a soft, “slightly earlier / on the early side / ahead of time” feeling.

In this sentence, 早めに suggests “I want to get it done in advance, before it becomes tight or urgent.”

What exactly is 早め? Is it an adjective, noun, or something else?

早め comes from the adjective 早い (early) plus め, which turns it into a kind of degree noun meaning “rather early / on the early side”.

早い = early (adjective)
早め = “an early-ish time/degree”

With に, it works as an adverb:

早めに出る = leave on the early side
早めに寝る = go to bed a bit early
早めに終わらせたい = want to finish a bit early / ahead of time

Why is it 終わらせたい and not 終わりたい?

This is about transitive vs intransitive verbs:

終わる = to end / to be over (intransitive; something ends by itself)
- 仕事が終わる = the work ends (by itself / naturally)
終わらせる = to finish something (transitive; you make it end)
- 仕事を終わらせる = you finish the work

In the sentence, 仕事 is something you actively finish, so we need the transitive form:

仕事を終わらせたい = I want to finish the work

仕事を終わりたい is ungrammatical, because 終わる doesn’t normally take a direct object with を in this sense.

Could I say 仕事を早めに終えたい instead of 終わらせたい?

Yes, 仕事を早めに終えたいです is grammatically fine.

Nuance:

終える also means “to finish / complete (something)”.
終える sounds a bit more formal/literary than 終わらせる, and is less common in casual speech.
終わらせる is very natural, everyday speech: “get it done / finish it”.

So both are correct:

終わらせたい → very common, neutral spoken style
終えたい → a bit more formal or “stiff”

What does the たい in 終わらせたい mean grammatically?

〜たい attaches to the masu-stem of a verb and expresses the speaker’s desire:

終わらせる → masu-stem: 終わらせ → 終わらせたい = want to finish

Grammar points:

It behaves mostly like an i‑adjective (it conjugates like 高い).
It’s used mainly for your own wants (or someone very close, in casual speech).
For a third person’s desire, Japanese often avoids 〜たい and uses 〜たがっている:
- 彼は仕事を早めに終わらせたがっています。
  “He seems to want to finish work early.”

Why is it 終わらせたいです and not just 終わらせたい? Is たい already polite?

〜たい itself is not polite; it’s neutral/informal.

To make it polite, you:

Use です after the 〜たい form:
- 終わらせたいです。 = polite
- 終わらせたい。 = plain

So:

終わらせたいです = “I want to finish (polite).”
終わらせたい = “I want to finish (casual).”

In conversation with coworkers, customers, etc., 〜たいです sounds suitably polite and is very common.

What is the function of を in 仕事を早めに終わらせたい?

を marks 仕事 as the direct object of the verb:

仕事を終わらせたい
→ “I want to finish the work.”

So:

仕事 = the thing being finished
終わらせたい = want to finish (it)

You cannot replace this を with で here; で would give a completely different meaning (place, means, etc.), and would be incorrect in this sentence.

Can I move the word order around, like 私は仕事を休みの前に早めに終わらせたいです? Does it change the meaning?

Yes, you can change the order of the middle parts; Japanese word order is fairly flexible as long as:

the verb (終わらせたいです) stays at the end, and
the particles (は, を, に, の) stay attached to the right words.

Examples that are all natural and mean essentially the same thing:

私は休みの前に仕事を早めに終わらせたいです。
私は仕事を休みの前に早めに終わらせたいです。
休みの前に私は仕事を早めに終わらせたいです。

The nuance can shift slightly (what you emphasize), but the basic meaning doesn’t change.

Is 私 necessary here? Could I just say 休みの前に仕事を早めに終わらせたいです?

You can absolutely drop 私, and native speakers often would.

休みの前に仕事を早めに終わらせたいです。

In Japanese, the subject (I/you/he/she) is often omitted if it’s obvious from context.
Using 私 is fine (a bit more explicit), but not required.

What is the difference between 休みの前に and something like 休みまでに?

Both relate to time before the break, but the nuance is different:

休みの前に
→ “before the break”
Focus is on the period that precedes the break. It’s looser, about “sometime before that period starts”.
休みまでに
→ “by the time it’s the break / by the break”
Focus is on a deadline: you must have it finished no later than the start of the break.

So:

休みの前に仕事を早めに終わらせたいです。
→ I’d like to get it done early, at some point before the break.
休みまでに仕事を終わらせたいです。
→ I want to finish it by the break (deadline feeling).