A városi lakók betartják a házirendet.

Hungarian has two forms of the definite article:

• a before a consonant sound
• az before a vowel sound

Here, both városi and házirendet begin with consonant sounds, so the sentence uses a:

• a városi lakók
• a házirendet

So this works much like choosing a or an in English, except it applies to the.

Városi means urban, city, or of the city.

It is formed from:

• város = city
• -i = an adjective-forming suffix

So:

• város → városi
• city → city-related / urban

This -i suffix is very common in Hungarian for making adjectives from places and nouns.

Lakók means residents, inhabitants, or occupants.

The singular is:

• lakó = resident / occupant

The plural ending is -k, so:

• lakó → lakók

The word comes from the idea of living somewhere. In many contexts, lakó suggests someone who lives in a particular place, building, or residence.

Because in Hungarian, an adjective placed directly before a noun usually does not take a plural ending. The noun shows the plural, not the adjective.

So:

• városi lakó = urban resident
• városi lakók = urban residents

Not:

• városiak lakók in this structure

This is different from English only in form, not in meaning. Hungarian simply marks plurality once, on the noun.

Yes, there can be a small difference.

• lakó often means a resident/occupant of a particular place, building, or dwelling
• lakos often means an inhabitant of a town, city, or country

Because the sentence also contains házirend (house rules / building rules), lakók feels very natural here: it suggests people living in a place where such rules apply.

Betartják comes from the verb betart.

In this sentence, it means:

• they keep
• they observe
• they obey
• they follow

Depending on context, English might translate it differently, but with rules, regulations, or instructions, keep/observe/follow are all common translations.

So betartják a házirendet means they are following or observing the house rules.

Because Hungarian verbs have different conjugations depending on whether the object is definite or indefinite.

Here the object is:

• a házirendet = the house rules / the house policy

That is a definite object, so Hungarian uses the definite conjugation.

For betart, the 3rd person plural present form is:

• betartják = they keep/observe it

Compare:

• betartanak egy szabályt = they obey a rule
• betartják a szabályt = they obey the rule

So the -ják ending helps show that the verb has a definite object.

Because házirendet is in the accusative case, which marks the direct object.

The dictionary form is:

• házirend

But as the object of the verb, it takes the accusative ending:

• házirend
  • -et → házirendet

The main accusative marker is -t, but Hungarian often inserts a vowel before it for pronunciation. Here that gives -et.

So:

• házirend = house rules / house policy
• házirendet = house rules / house policy as the object

Grammatically, házirend is singular in Hungarian.

However, its meaning is often collective. It refers to a whole set of rules or regulations. That is why English often translates it as:

• house rules
• building rules
• internal regulations

So Hungarian uses a singular noun for something English often expresses with a plural noun.

This word order is quite normal and neutral:

• A városi lakók = topic/subject
• betartják = verb
• a házirendet = object

So the sentence presents a straightforward statement.

Hungarian word order is flexible, but changing it often changes the emphasis. For example:

• A házirendet a városi lakók tartják be.

This puts more emphasis on a házirendet or creates a contrast.

Because be- is a verbal prefix, and Hungarian prefixes often separate from the verb in certain situations, especially with:

• negation
• focus
• some question patterns

In the neutral affirmative sentence, the prefix stays attached:

• betartják

But with negation, it usually separates:

• A városi lakók nem tartják be a házirendet.

That means The city residents do not follow the house rules.

So seeing betartják and tartják be is normal: they are related forms of the same prefixed verb.

It depends on context.

By itself, városi lakók most naturally means:

• city residents
• urban residents

But because the sentence also contains házirend, which often refers to the rules of a building, dormitory, apartment house, or similar place, the phrase may feel like the residents living in the city building/place being discussed.

So the exact English wording depends on the situation, even though the Hungarian grammar stays the same.