Learn Hardcore Japanese: zikan sae areba, syukudai wo hayame ni owarasemasu. - As long as I have time, I will finish my homework early.

In the pattern Nさえ V-ば, さえ means “if only / as long as.” So 時間さえあれば = “as long as there is time / if only I have time.” It presents “time” as the minimal requirement for the result to happen.

Why is there no particle after 時間? Shouldn’t it be 時間が?

With さえ, core case particles like が and を are typically dropped: 時間さえあれば, これさえあれば. Particles such as に/へ/で/から/まで can remain when they are semantically needed: 東京でさえ買える, 子どもにさえ分かる.

Can I say 時間がさえあれば?

No. さえ attaches directly to the noun and replaces が/を. Say 時間さえあれば or (a heavier variant) 時間がありさえすれば.

Is 時間がありさえすれば also correct? What’s the nuance difference vs 時間さえあれば?

Yes. It uses the verb pattern V-ます-stem + さえ + すれば: ありさえすれば. It sounds a bit more formal/emphatic (“if there exists even a bit of time”). 時間さえあれば is shorter and more common in everyday speech.

Why use the ば-conditional (あれば) here? Could I use たら or なら?

さえ most naturally pairs with 〜ば. 時間さえあれば is the textbook, most idiomatic choice. 時間さえあるなら is also fine and common. 時間さえあったら is sometimes heard, but 〜ば is the safest, most standard with さえ.

How is さえ different from だけ?

だけ = “only/just,” a neutral limiter: 時間だけある (“I have only time”).
Nさえ V-ば = “if only/as long as,” expressing a sufficient condition: 時間さえあれば.
Plain Nさえ (without 〜ば) means “even”: 彼でさえ知らない (“Even he doesn’t know”).

What exactly does 早めに mean? How is it different from 早く?

早めに means “on the early side / earlier than usual / a bit early.” The suffix 〜め softens the degree and implies a proactive choice to be somewhat early.
早く means “early” or “quickly” without that “somewhat/earlier than usual” nuance.
Compare: 今日は早めに寝る (go to bed a little earlier than usual) vs 今日は早く寝る (go to bed early).

Is に necessary after 早め?

Yes in standard usage. 早め is a noun-like form; use に to make it adverbial: 早めに終わらせます. In casual speech you may hear 早め終わらせる, but 早めに is the safe, correct form.

Why use 終わらせます instead of 終わります?

終わる is intransitive (“to end/finish” by itself). You can’t say 宿題を終わります.
To take a direct object (宿題を), use a transitive verb: 終える or the causative-like 終わらせる. Hence 宿題を終わらせます or 宿題を終えます = “I will finish my homework.”

Is 宿題を終えます also correct? Any nuance difference vs 終わらせます?

Yes. 終える is a straightforward transitive “to finish/complete” and can sound a bit crisper or more formal. 終わらせる (causative of 終わる) is very common in conversation; it can feel slightly more colloquial or “to get it over with.”

Does 終わらせます mean “make someone else finish” here?

No. With tasks/things as the object (e.g., 宿題を), 終わらせる commonly means “to get (something) finished.” It means “make/let it be over,” not “force a person.” If you want “make someone finish,” you’d specify a person: 子どもに宿題を終わらせる.

Could I say 宿題が早めに終わります instead?

Yes. That uses the intransitive 終わる with 宿題 as the subject: 宿題が早めに終わります = “The homework finishes early / I get done with my homework early.”

宿題を終わらせます emphasizes you as the doer finishing it.
宿題が終わります focuses on the event of the homework being finished.

What’s the difference between 早く and 速く? Which one fits here?

早く = early (time).
速く = quickly/fast (speed).
Here it’s about time (“finish earlier”), so use 早めに or 早く, not 速く.

What does を do in 宿題を?

を marks the direct object of a transitive verb. Since 終わらせる/終える are transitive, the thing being finished takes を: 宿題を終わらせます / 終えます.

Who is the subject? Why is it omitted?

Japanese often omits subjects when they’re clear from context. With 〜ます, it’s typically “I/we.” You could add 私は/僕は if needed: 時間さえあれば、私は宿題を早めに終わらせます.

Can I switch the clause order or drop the comma?

The comma is optional: 時間さえあれば宿題を早めに終わらせます is fine.
You can put the condition after, but it’s less natural: 宿題を早めに終わらせます、時間さえあれば. In Japanese, conditional clauses usually come first.