Learn Hardcore Hungarian: Ma a park helyett a könyvtárba megyek. - Today I go to the library instead of the park.

Helyett is a postposition meaning “instead of.” It comes after the noun it relates to. In the sentence, a park helyett = “instead of the park.” The noun before it stays in its base form (no extra case ending).

Examples:
- János helyett megyek. = I’m going instead of János.
- With pronouns, it usually takes personal endings: helyettem (instead of me), helyetted, helyette, helyettünk, helyettetek, helyettük.

Why is it könyvtárba and not könyvtárbe?

Because of vowel harmony. The in-to (illative) ending is -ba after back-vowel words and -be after front-vowel words.

Back vowels: a, á, o, ó, u, ú → -ba (e.g., boltba “into the shop”)
Front vowels: e, é, i, í, ö, ő, ü, ű → -be (e.g., kertbe “into the garden”) Although könyvtár has both front (ö) and back (á) vowels, mixed words like this normally take back-vowel suffixes, so it’s könyvtárba.

What’s the difference between -ba/-be and -ban/-ben?

-ba/-be = movement into: a könyvtárba megyek “I’m going into the library.”
-ban/-ben = location inside: a könyvtárban vagyok “I’m in the library.”

Could I say könyvtárhoz megyek instead of könyvtárba megyek?

You could, but it means something different:

-hoz/-hez/-höz = (up) to, toward (up to the building, not necessarily going inside): a könyvtárhoz megyek.
-ba/-be = into (you intend to go inside): a könyvtárba megyek. Your sentence specifically contrasts going inside the library with going to the park.

Why does park have no case ending in a park helyett?

Because helyett is a postposition that takes a noun in its base (nominative) form. The postposition itself expresses the relationship (“instead of”), so the noun park doesn’t get an extra suffix there.

Do I need to say the subject pronoun én?

No. The verb ending in megyek already shows “I.” Adding Én adds emphasis or contrast (“I, as opposed to someone else”).

Neutral: Ma a park helyett a könyvtárba megyek.
Emphatic: Én ma a park helyett a könyvtárba megyek.

Can I change the word order, and what changes if I do?

Yes, Hungarian word order reflects emphasis. The focused element usually stands right before the verb.

Ma a park helyett a könyvtárba megyek. (focus on destination: “to the library”)
Ma a könyvtárba megyek a park helyett. (very similar meaning; the “instead of the park” part is de-emphasized at the end)
Ma a park helyett megyek a könyvtárba. (focus on the “instead of the park” contrast) All are grammatical; choose the one that puts the emphasis where you want it.

Why is the article a used before both nouns? Can I drop it?

Hungarian a/az is the definite article (“the”). You can often drop the article with institutions to speak about the activity in general:

(A) könyvtárba megyek. With the article = a specific library; without it = “going to the library” as an activity. After helyett, the article signals specificity: a park helyett = “instead of the park (we had in mind).” If you say park helyett, it sounds more general (“instead of going to a park”).

How would I express the same idea with explicit negation and “but rather” (hanem)?

Use: Ma nem a parkba megyek, hanem a könyvtárba. That’s “Today I’m not going to the park, but rather to the library.” It’s a very common alternative to using helyett.

How do I say “instead of me/you/him/her/us/them”?

Attach personal endings to helyett:

helyettem (instead of me)
helyetted (instead of you, sg.)
helyette (instead of him/her)
helyettünk (instead of us)
helyettetek (instead of you, pl.)
helyettük (instead of them) Example: Helyettem mész a könyvtárba. = You’re going to the library instead of me.

Any pronunciation tips for Ma a park helyett a könyvtárba megyek?

Stress is always on the first syllable of each word.
gy in megyek sounds like a soft “dy.”
ly in helyett is pronounced like English “y.”
Double tt in helyett is a long consonant; hold it slightly longer.
ö in könyv- is a front rounded vowel (like German ö).
ny is a palatal “ny” sound (like Spanish ñ).

Could I use the verb prefix be- (to go in) here?

Yes:

Ma bemegyek a könyvtárba. = “I’ll go in(to) the library.” If you keep the focused destination before the verb, the prefix moves after the verb:
Ma a könyvtárba megyek be. Your original sentence without a prefix is also fine; it already specifies the “into” meaning with -ba.

How do I say it in the past or future?

Past: Tegnap a park helyett a könyvtárba mentem. (mentem = I went)
Future: Hungarian often uses the present for near-future plans: Holnap a könyvtárba megyek. You can also say Holnap a könyvtárba fogok menni, but it’s less necessary in everyday speech.

How do plurals work with helyett and destinations?

Pluralize the nouns as usual:

parkok helyett = instead of parks
könyvtárakba = into libraries Example: Ma a parkok helyett a könyvtárakba megyek (odd in meaning, but grammatically fine). Normally you’ll keep them singular to talk about specific places.