Learn Hardcore Dutch: De kalender hangt tegenover de voordeur zodat iedereen hem ziet. - The calendar hangs opposite the front door so that everyone sees it.

Yes, one word. tegenover is a preposition meaning “opposite” or “across from.” You say tegenover de voordeur, not tegenover van or tegen over.

Do I need to add aan de muur?

It’s optional. hangen already implies it’s attached/suspended, usually from a wall. You can add it for clarity: De kalender hangt aan de muur tegenover de voordeur.

What’s the difference between zodat and omdat (and opdat)?

zodat: “so that,” expressing result or intended outcome.
omdat: “because,” giving the reason.
opdat: “in order that,” very formal/literary; in modern Dutch, zodat usually covers this.

Why is the order zodat iedereen hem ziet and not zodat iedereen ziet hem?

After a subordinating conjunction like zodat, Dutch puts the finite verb at the end: ... iedereen hem ziet. Object pronouns (like hem) come before that final verb. In a main clause it would be Iedereen ziet hem.

Why hem and not het?

Because kalender is a de-word (common gender, masculine), so the object pronoun is hem. het is used for neuter nouns: het boek → ik zie het.

Is kalender a de- or het-word? How can I tell?

It’s de kalender. With compounds, the gender is that of the head (last part). You mainly have to memorize noun gender, but knowing the base word helps: de deur → de voordeur; het nummer → het huisnummer.

Could I say zodat iedereen hem kan zien?

Yes. zodat iedereen hem ziet states the (expected) result; zodat iedereen hem kan zien highlights the possibility/visibility. Both are natural here.

Should there be a comma before zodat?

It’s optional. Many writers skip it in short sentences. You may add one for readability: De kalender hangt tegenover de voordeur, zodat iedereen hem ziet.

Why ziet (singular) after iedereen?

iedereen is grammatically singular, so the verb is singular: iedereen ziet / iedereen is (not zien / zijn).

What’s the difference between tegenover and aan de overkant van?

Both can mean “opposite,” but:

tegenover = directly opposite/across from.
aan de overkant van = on the other side of something (street/river): Aan de overkant van de straat staat een bakker.

Can I front the location: Tegenover de voordeur hangt de kalender?

Yes. You can topicalize the location. The verb still stays in second position: Tegenover de voordeur hangt de kalender, zodat iedereen hem ziet.

Can I use die instead of hem for the calendar?

Only if you mean the demonstrative “that one”: zodat iedereen die ziet (contrast/emphasis). The neutral default for a previously mentioned de-word object is hem. Note: in Flanders you may hear feminine pronouns for feminine nouns; in the Netherlands hij/hem is common for inanimate de-words.

What’s the difference between hangen and ophangen?

hangen = to be hanging (state): De kalender hangt tegenover de voordeur.
ophangen = to hang (something) up (action): Ik hang de kalender op. Past forms: hing/gehangen; separable ophangen → hing op/opgehangen.

Any pronoun traps with tegenover?

With neuter or non-specific reference, use R‑pronouns: er/daar/waar + tegenover.

Hij hangt er tegenover (= opposite it/there).
Not: Hij hangt tegenover het. With people you can use hem/haar: tegenover hem.

Pronunciation tips?

hangt: pronounce the -ngt cluster; the g is a hard guttural in most accents.
tegenover: stress on -no-: te-ge-NO-ver; the g is the same hard sound.
hem often reduces to ’m in casual speech: zodat iedereen ’m ziet.