Learn Hardcore Hungarian: Ez az utca olyan hosszú, mint az út a folyó mellett. - This street is as long as the road by the river.

Hungarian always uses the definite article with demonstratives, and the article has two forms: a before a consonant and az before a vowel. Since utca starts with the vowel sound u, you must say ez az utca. For comparison:

ez a ház (this house; consonant h-)
ez az utca (this street; vowel u-)
az az autó (that car; here the demonstrative is az “that,” and the article a/az also appears before the noun)

Why do we need both the demonstrative and the article (ez + a/az) in Hungarian?

With a demonstrative (ez/az = this/that), Hungarian requires the regular definite article before the noun: ez a/az + noun, az a/az + noun. Leaving the article out (e.g., ez utca) is ungrammatical in standard Hungarian.

How does the pattern olyan … mint work here?

Olyan + adjective, mint + comparison target expresses equality of degree (“as … as”). In the sentence: olyan hosszú, mint … = “as long as …”. You can use it with most adjectives and many adverbs:

olyan gyors, mint te = as fast as you
olyan hangosan beszél, mint a tanár = speaks as loudly as the teacher

Can I use ugyanolyan instead of olyan?

Yes. Ugyanolyan …, mint … adds emphasis meaning “exactly the same (kind/degree) … as …”. Here:

Ez az utca ugyanolyan hosszú, mint az út a folyó mellett. Both are fine; ugyanolyan is just a bit stronger.

Could I say annyira hosszú, mint instead of olyan hosszú, mint?

You can, and it’s grammatical: Annyira hosszú, mint … also means “as long as …”. In practice, olyan …, mint is the default with adjectives; annyira …, mint is a stylistic alternative and often used with adverbs or when talking about intensity/degree.

Why is there a comma before mint?

In standard Hungarian punctuation, when mint introduces the second part of an equality comparison after words like olyan/ugyanolyan/akkora/ugyanakkora/annyi/ugyanannyi, a comma is normally used: Olyan hosszú, mint …. You’ll see this consistently in edited texts.

Where is the verb “to be”? Why isn’t van included?

In present tense, 3rd person equational/predicative sentences with adjectives or nouns usually omit van. So you say:

Ez az utca hosszú. (not: Ez az utca hosszú van.)
Ez az utca olyan hosszú, mint … (no van) You do use it in past/future: Ez az utca olyan hosszú volt/lesz, mint …

Is utca the same as út?

No. Utca = “street” (typically inside a town/city). Út = “road/route,” often outside towns or referring to major roads, highways, or a route in general. Examples:

Kossuth utca = Kossuth Street (urban)
6-os út = Route 6 / Highway 6 (intercity/major road)

What does mellett add, and could I use something else like mentén or partján?

mellett = “beside/next to/by,” focusing on adjacency: az út a folyó mellett = the road next to the river.
mentén = “along,” focusing on extending alongside the length: az út a folyó mentén = the road running along the river.
partján = “on the (river)bank of”: az út a folyó partján = the road on the river’s bank. All are possible, but the nuances differ. Choose based on what you want to emphasize.

Is there a shorter adjectival form for “the road by the river”?

Yes: a folyó menti út means “the riverside road” or “the road along the river,” using menti (derived from mentén) as an attributive adjective.

Why is it az út but a folyó?

Same article rule as before: az before a vowel sound, a before a consonant sound. Út starts with vowel ú, so az út. Folyó starts with consonant f, so a folyó.

Could I drop the article before folyó and just say folyó mellett?

Not in standard prose. You generally need an article: a folyó mellett (the river) or egy folyó mellett (by a river). Bare nouns without an article are limited to special contexts (e.g., headlines, some set phrases).

Do adjectives agree in number? What happens in the plural?

Predicate adjectives agree in number. With a plural subject, add the plural ending:

Singular: Ez az utca hosszú.
Plural: Ezek az utcák hosszúak. For equality: Ezek az utcák olyan hosszúak, mint …

Could I express “longer than” instead?

Yes. Use the comparative:

Ez az utca hosszabb, mint az út a folyó mellett. Hungarian also allows the ablative comparison: Ez az utca hosszabb az útnál (a folyó mellett). For equality, stick with olyan …, mint (don’t use -nál/-nél).

Is the word order fixed? Can I start with the road?

Hungarian word order is flexible and topic–comment oriented. You can say:

Az út a folyó mellett olyan hosszú, mint ez az utca.
Olyan hosszú ez az utca, mint az út a folyó mellett. All are natural; the chosen topic usually comes first.

Why isn’t it úton/utcán? When do I add the -n/-on/-en/-ön “on” ending?

You add superessive endings (-n/-on/-en/-ön) when you mean physical location on a surface: az úton (on the road), az utcán (on the street). In our sentence, az út is just a noun being described (“the road”), not a location expression, so it stays in the base form.

Any pronunciation tips for tricky parts like utca and hosszú?

utca: c is pronounced like English “ts.” Say something like “OOT-tsa.” The final a is a short, back vowel [ɒ], similar to the “o” in British “got.”
hosszú: double sz is still a single “s” sound (like English “s,” not “sh”). The final ú is a long “u” sound; vowel length matters in Hungarian.
Stress is always on the first syllable: EZ az U-tca O-lyan HOSszú, mint AZ út a FO-lyó MELlett.