यह फ्लैट रोशन और सुरक्षित है।

यह means this. It is the demonstrative used for something near the speaker, so यह फ्लैट means this flat/apartment.

In careful written Hindi, यह is the standard singular form. In everyday speech, many speakers pronounce it more like ये, but in formal writing you normally use यह for singular.

Hindi usually puts the verb at the end, so a sentence like this often follows the pattern:

subject + description + verb

So:

• यह फ्लैट = this flat
• रोशन और सुरक्षित = bright and safe
• है = is

That is why the is equivalent, है, comes at the end.

है is the present-tense form of the verb to be for he/she/it/this/that and singular nouns in sentences like this.

So in this sentence, है links the subject (यह फ्लैट) with its qualities (रोशन और सुरक्षित), just like is in English.

Compare:

• यह फ्लैट सुरक्षित है। = This flat is safe.
• यह कमरा बड़ा है। = This room is big.

Hindi can list multiple descriptions before the final verb. Here the flat is being described as both:

• रोशन = bright / well-lit
• सुरक्षित = safe / secure

They are connected by और, which means and.

So the structure is very natural: noun + adjective + और + adjective + है

Most of the time, yes. In a sentence like this, और is the normal word for and.

Examples:

• चाय और कॉफ़ी = tea and coffee
• बड़ा और सुंदर घर = a big and beautiful house

In other contexts, और can also mean something like more or else/further, but here it clearly means and.

In this sentence, they do not change.

Many Hindi adjectives are variable, meaning they change form depending on gender/number, such as:

• अच्छा (masculine singular)
• अच्छी (feminine singular)
• अच्छे (masculine plural / respectful)

But रोशन and सुरक्षित are commonly used as invariable adjectives, so their form stays the same:

• यह फ्लैट रोशन है।
• यह इमारत रोशन है।
• ये कमरे रोशन हैं।

Same with सुरक्षित.

फ्लैट is a borrowed word from English, and in Hindi it is usually treated as masculine.

In this sentence, that does not create any visible change, because:

1. रोशन and सुरक्षित do not change here.
2. है is the same for masculine and feminine singular.

So even if you were unsure of the gender, this particular sentence would still look the same.

Gender becomes more noticeable with adjectives or verbs that do change, for example:

• यह फ्लैट बड़ा है। = This flat is big.
  Here बड़ा shows masculine singular.

Hindi normally does not use articles like English a, an, and the.

So यह फ्लैट can naturally correspond to this flat without any separate article word.

More generally:

• कमरा बड़ा है। can mean The room is big or A room is big, depending on context.
• यह कमरा already clearly means this room, so no article is needed.

Context usually tells you the exact nuance.

Yes, but it is not exactly the same emphasis.

• यह फ्लैट रोशन और सुरक्षित है।
  This is the most straightforward way to say that the flat is bright and safe.

• यह रोशन और सुरक्षित फ्लैट है।
  This sounds more like This is a bright and safe flat or This is the bright and safe flat, depending on context. Here the adjectives are placed directly before the noun.

Both are grammatical, but the original sentence is the more natural pattern when you are simply stating qualities about the flat.

It is a very common loanword from English. Modern Hindi uses many English-origin words, especially for housing, technology, transport, and office life.

So फ्लैट is perfectly normal in everyday Hindi, especially in urban contexts. Depending on region or register, you might also hear words such as अपार्टमेंट, but फ्लैट is very common.

फ्लैट represents the English word flat fairly closely.

A rough guide:

• फ्ल = fl
• ै = the vowel sound in flat
• ट = a retroflex t sound, made with the tongue curled slightly back

So it sounds close to flat, but with a Hindi-style ट at the end.

Because the subject is singular: यह फ्लैट = this flat.

Use:

• है for singular
• हैं for plural (and also for respectful singular)

Compare:

• यह फ्लैट सुरक्षित है। = This flat is safe.
• ये फ्लैट सुरक्षित हैं। = These flats are safe.

So है matches the singular subject.

Normally, no in standard Hindi.

If you use ये to mean these, then the noun is plural, and the verb should also be plural:

• ये फ्लैट रोशन और सुरक्षित हैं। = These flats are bright and safe.

For singular this flat, standard written Hindi is:

• यह फ्लैट रोशन और सुरक्षित है।

In casual speech, some people say ये even for singular this, but learners should first master the standard written distinction:

• यह = this
• ये = these