Learn Hardcore Japanese: henpin ha nanoka kurai made kanou desu ka? - Is returning possible for about seven days?

It makes 返品 the topic: “As for returns, is it possible up to about seven days?” The full idea is something like 返品は（いつまで）可能ですか. You could also ask more simply with a verb: 返品できますか. Using が here (返品が…) would sound odd; stick with 返品は or a verb-only question.

What exactly does 返品 mean? Is it the same as 返却, 返金, or 交換?

返品: returning an item you purchased (often expecting a refund or exchange).
返却: returning something you borrowed or rented (library book, rental).
返金: refund of money.
交換: exchanging one item for another. So this sentence is about whether returning a purchase is allowed.

How do I read 七日 here?

Read it as なのか (nanoka). For durations, you can also say 七日間（なのかかん） to make “for seven days” explicit. The reading しちにち exists but is less common in everyday speech. For the date (the 7th of the month), it’s also なのか.

What does 七日くらいまで mean exactly?

七日: seven days (or the 7th day).
くらい: about/approximately.
まで: up to/until (limit). Together: “up to about seven days.” It suggests an approximate deadline, not a precise one.

Is まで inclusive of the 7th day?

By default, まで is inclusive (“up to and including”). With くらい, the boundary is fuzzy, so speakers treat it as “roughly up to the 7th day.” Official policies usually avoid ambiguity and say 七日以内 (“within seven days,” inclusive).

Should this be まで or までに?

まで highlights a limit: “returns are possible up to X.”
までに is “by/before X” (deadline for doing something). For a policy, both can work but in different wordings:
返品は七日まで可能ですか。 (up to the 7th day)
七日までに返品できますか。 (can I return by the 7th day?) Stores often use 七日以内 (“within seven days”).

What’s the difference between くらい, ぐらい, ほど, and ごろ here?

くらい / ぐらい: both mean “about/approximately.” ぐらい is a bit more colloquial; either is fine: 七日くらい/ぐらい.
ほど: also “about,” a touch more formal or written: 七日ほど.
ごろ: used for points in time (e.g., 3時ごろ, 7日ごろ). For deadlines, ごろまで is unusual; use くらい/ほど or 以内/までに instead.

Do I need to say “from when”? From purchase date or delivery date?

If you don’t specify, people often assume “from the purchase date,” but it’s safer to state it:

購入日から七日以内 (within seven days from the purchase date)
お届けから七日以内 (from delivery/receipt)

Is 可能です natural here? What about できます or 受け付けています?

All are used, with nuance:

返品は七日くらいまで可能ですか。 Formal, sign-like.
七日くらいまで返品できますか。 Natural, everyday.
七日くらいまで返品を受け付けていますか。 Emphasizes acceptance/processing. For extra politeness: 恐れ入りますが、購入日から七日以内に返品できますか。

Why not use を after 返品?

With 可能です, 返品 is the topic, not a direct object, so を doesn’t fit. Don’t say 返品を可能ですか (unnatural). If you use a verb, you can say （商品を）返品できますか.

Is the word order fixed? Can I move the time phrase?

You can reorder for emphasis:

返品は七日くらいまで可能ですか。 (neutral)
七日くらいまでは返品可能ですか。 (emphasizes the limit)
七日くらいまで返品できますか。 (verb phrasing) All are acceptable. Adding は after まで (…までは) emphasizes that specific limit.

七日 vs 七日間 vs 一週間—what should I use?

七日 can mean “seven days” or “the 7th day.”
七日間 clearly means a span of seven days.
一週間 is “one week.” Typical policy phrasing: 購入日から七日以内 or 購入日から一週間以内. With まで, you’d say 七日まで, not 七日間まで.

Is the question mark necessary when I already have か?

No. …ですか。 is perfectly correct. In casual or customer-facing writing, …ですか？ is common. In very formal documents, stick to 。 without ？.

Should I use ご返品?

Stores often use honorifics for the customer’s actions: ご返品は七日以内で承っております. As a customer asking, you typically say 返品 (no ご): 返品は七日以内にできますか。 Using ご返品 for your own action can sound overly deferential or off.

Can I say 一週間くらいまで?

It’s understandable, but for policies 一週間以内 sounds more natural than 一週間くらいまで. If you want approximate wording, 一週間ほどまで or simply 一週間くらい in conversation is fine, but businesses prefer precise 以内/まで.

Is there a more precise way than 七日くらいまで?

Yes. Use:

購入日から七日以内 (within seven days from purchase)
購入日を含めて七日間 (for seven days including the purchase day)
購入日の翌日から起算して七日以内 (within seven days counting from the day after purchase; very precise/legalistic)

How would I ask the same thing more casually?

返品って、七日くらいまでできる？
買ってから一週間くらいまでいけますか？ (still polite-ish) Both are natural in everyday conversation.