Learn Hardcore Japanese: mazu genkan no hako wo naka ni hakobu. - First, carry the box at the entrance inside.

Yes. まず is an adverb meaning “first; to begin with.” It often starts instructions or sequences of actions. In normal writing you’d punctuate it as まず、.

Why is it 玄関の箱? Does の mean “the entrance’s box”? Should it be 玄関から?

の links nouns and can show association or location. 玄関の箱 means “the box at/by the entryway” (i.e., the box located there). If you want to express origin (“from the entrance”), use 玄関から:

玄関から箱を中に運ぶ = “Carry the box from the entrance to the inside.”

Is 玄関 the same as 入口?

Not quite.

玄関 (げんかん): the entryway/foyer of a house or apartment (inside area by the front door).
入口 (いりぐち): the entrance to any place (store, park, building, etc.).

Is 玄関の箱 natural? What if it’s a package left outside the door?

It can be natural if you mean “a box associated with the entryway.” For a delivered parcel by the door, 玄関先 (“just outside the front door”) or 玄関の前 is more idiomatic:

玄関先の箱を中に運ぶ
玄関の前にある箱を中に運ぶ
Or specify existence: 玄関に置いてある箱を中に運ぶ

Why are both を and に used? What do they mark?

を marks the direct object: 箱 (the thing being moved).
に marks the destination: 中 (“inside”).
So 箱を中に運ぶ = “carry the box to the inside.”

Can I use へ instead of に in 中に運ぶ?

Yes. 中へ運ぶ is fine; へ emphasizes direction “toward,” に emphasizes the destination. The difference here is small. Note: with verbs like 入れる, use に (e.g., 中に入れる, not ×中へ入れる).

Could I drop 中 and just say 箱を運ぶ?

You can, but you’ll lose the “inside” destination. Options:

Keep it general: 箱を運ぶ (“carry the box”).
Specify a place instead of 中: 家に運ぶ, 部屋に運ぶ, リビングに運ぶ.
If you want “inside,” use 中に or be explicit: 家の中に.

Would 箱を中に入れる be better than 運ぶ?

Different focus:

入れる = “put/place into,” focusing on insertion.
運ぶ = “carry/transport,” focusing on moving it.
A very natural choice is the compound verb 運び入れる (“carry in/into”):
箱を家の中に運び入れる.

Who is the subject here? Is this a command?

Japanese often omits the subject. Depending on context, it could be “I/we” (plan or diary) or an instruction to “you.” In manuals and lists, the plain form 〜する often functions like a step/imperative. Polite or explicit versions:

まず、玄関の箱を中に運びます。 (polite)
まず、玄関の箱を中に運んでください。 (request)

What tense is 運ぶ?

Plain non-past. It can mean future (“will carry”), habitual (“carry (as a routine)”), or an instruction step. With まず, it reads as the next action to take.

Why not 玄関で? I thought で marks places.

で marks the place where an action occurs. 玄関で運ぶ would mean “carry (it) in the entryway,” not “from there.” To show origin and destination, use から and に/へ:

玄関から箱を中に運ぶ.

What’s the difference between 運ぶ and 持っていく / 持ってくる?

運ぶ: to transport/carry (often heavier/formal/neutral about toward/away).
持っていく: to take (away from the speaker’s current location).
持ってくる: to bring (toward the speaker’s location).
Example:
箱を中に運ぶ (neutral)
Speaker is outside and talking to someone inside: 箱を中に持っていく (“I’ll take it in”).
Speaker is inside and wants it brought in: 箱を中に持ってきて (“bring it in”).

Can I change the word order?

There’s some flexibility, but the default is object before destination:

Default: 玄関の箱を中に運ぶ.
You can front the destination for emphasis: 中に、玄関の箱を運ぶ (okay in speech/writing with a pause).
Avoid scattering elements in a way that’s hard to parse.

Is using spaces between words okay in Japanese?

Standard Japanese doesn’t use spaces between words. Write it as:

まず、玄関の箱を中に運ぶ。
Spaces are sometimes used in learning materials only.

How are the words read?

まず (kana is standard; kanji 先ず exists but is rare)
玄関 (げんかん)
箱 (はこ)
中 (なか) in 中に (なかに) here
運ぶ (はこぶ)

Is 中 the same as 内?

Both can mean “inside,” but:

中 (なか) is the default for physical inside.
内 (うち) is more formal/abstract or group-internal; うち also means “our home/our company.”
For “carry inside (the house),” use 中: 家の中に.

What if I want to be very clear it’s a package left outside?

Natural options:

まず、玄関先の荷物を家の中に運ぶ。
まず、玄関の前に置いてある箱を家の中に運ぶ。
まず、宅配便の箱を家の中に運ぶ。

Is まずは different from まず?

まずは adds a slight “to start with/for now” nuance and can sound a bit softer or topic-like:

まずは、玄関の箱を中に運びます。 (polite, soft lead-in)
Both are fine at the start of step-by-step instructions.

How would I connect the next step, like “Then open it”?

Use a sequence connector such as それから or 次に:

まず、玄関の箱を中に運ぶ。それから、開ける。
Polite: まず、玄関の箱を中に運びます。それから、開けます。