Learn Hardcore Japanese: kanozyo ha yobi no kozeni wo saihu ni irete oku you ni site iru. - She makes sure to keep spare coins in her wallet.

It means “makes a point of / tries to keep doing” and emphasizes a deliberate, ongoing habit or policy. With a plain non-past verb phrase before it, bold V-plain + ようにしている says the subject consistently tries to ensure that action happens. It’s stronger than simply “does,” because it highlights conscious effort.

bold ようにする: “try to (do) on a given occasion; make an effort”
bold ようにしている: “make it your habit/policy to (do); keep making sure”

What does bold ておく in bold 入れておく mean?

bold ておく is an auxiliary that means “do something in advance/for later” or “do and leave it as is.” Here, bold 入れておく is “put (the coins) in and keep them there” as preparation for future needs.

How is bold 入れておく different from bold 入れてある and bold 入れている?

bold 入れておく: You (will) put them in and keep them there for future convenience (speaker’s perspective on purpose/preparation).
bold 入れてある: They have been put in (by someone) and are now in that state; focuses on the resulting state, not the intention.
bold 入れている: “is putting/keeps in” can describe an ongoing action or a general state/habit, but without the preparatory nuance of bold おく.

Why use both bold 入れておく and bold ようにしている? Isn’t that redundant?

They stack nicely and are not redundant:

bold 入れておく describes the kind of action (put and keep for later).
bold ようにしている says she makes it a habit/policy to do that action. Together: “She makes a point of keeping (by putting and leaving) spare change in her wallet.”

Can you break down the grammar of the whole sentence?

bold 彼女は: topic “as for her”
bold 予備の: “spare/reserve” (a noun used attributively with の)
bold 小銭を: direct object “spare change”
bold 財布に: target/destination “into the wallet”
bold 入れて: て-form of 入れる “to put in”
bold おく: auxiliary “do in advance/leave as is”
bold ように: “so that/in such a way that”
bold している: “is making a habit/keeps doing”

Overall: “As for her, she makes it a policy to put spare change into her wallet and keep it there.”

Why is bold に used after 財布 instead of bold を?

With verbs like bold 入れる (“put in/into”), the destination or container takes bold に. So bold 財布に is “into the wallet.” bold 財布を would make “wallet” the direct object (“to put the wallet [somewhere]”), which isn’t the meaning here.

Why is bold を used after 小銭 and not bold が?

bold を marks the direct object of the action: the thing being put in. bold 小銭を入れる = “put in the coins.” bold が would mark the subject (e.g., 小銭が入る “coins go in”), which changes the structure and meaning.

What exactly does bold 予備の mean, and how is it different from bold 余分な?

bold 予備の: “spare/backup/reserve” (kept for emergencies or just in case). Very natural with items kept on hand, e.g., 予備の電池 (spare batteries).
bold 余分な: “extra/surplus (often more than needed, sometimes unnecessary).” 余分な小銭 could sound like “unnecessary extra change,” not a purposeful reserve.

Could I say bold 予備に小銭 instead of bold 予備の小銭?

bold 予備に can work as an adverbial (“as a spare/for backup”), but here bold 予備の小銭 naturally labels the coins themselves as the reserved stash. bold 予備に小銭を財布に入れておく is grammatical, but bold 予備の小銭 sounds more idiomatic for “spare change.”

How flexible is the word order?

Japanese allows some flexibility as long as modifiers stay with what they modify and the verb is final. These are all fine:

彼女は予備の小銭を財布に入れておくようにしている。
彼女は財布に予備の小銭を入れておくようにしている。
予備の小銭を彼女は財布に入れておくようにしている。 Keep bold 予備の attached to bold 小銭 and leave the verb phrase at the end.

What’s the role of bold は on 彼女? Could it be bold が?

bold は marks the topic (“as for her”) and is natural if she’s already known or being contrasted. bold が would mark her as the grammatical subject/new info focus, which is possible but shifts the nuance to “It is she who…” and is less typical for neutral narration here.

What’s the difference between bold ようにしている and bold ことにしている?

Both can describe habits/rules, but:

bold ようにしている: emphasizes ongoing effort/attentiveness (“I make sure to…”).
bold ことにしている: emphasizes a personal decision/rule you’ve set (“I’ve decided/made it my rule to…”). In many contexts they overlap; bold ことにしている can feel slightly firmer as a self-imposed rule.

How would I make this more polite or more casual?

Polite: 彼女は予備の小銭を財布に入れておくようにしています。
Casual (spoken): 彼女は予備の小銭を財布に入れておくようにしてる。
Very casual contraction: 入れておく → 入れとく (彼女は…入れとくようにしてる). Use contractions in informal speech only.

How do I negate it, like “she tries not to keep spare change in her wallet”?

Negate the bold おく part inside: 彼女は予備の小銭を財布に入れておかないようにしている. This means she makes a point of not keeping spare change there.

Could I use bold ために instead of bold ように?

Not here. bold ように after a verb phrase makes the idiom bold V-plain + ようにしている (“make it a habit to V”). bold ために expresses purpose (“in order to”), and swapping it would break the pattern. If you want purpose, use a different structure, e.g., 念のため、小銭を財布に入れておく (“just in case, I keep change in my wallet”).

What are the readings of the key words?

彼女: かのじょ
予備: よび
小銭: こぜに
財布: さいふ
入れる: いれる You’ll often hear the whole key phrase as: いれておくようにしている. In casual speech, いれとくようにしてる.