बहन ऊपर कमरे में पढ़ती है, और भाई नीचे रसोई में खाता है।

Because the verb in Hindi agrees with the subject’s gender and number in this kind of sentence.

• बहन is feminine singular, so we get पढ़ती है
• भाई is masculine singular, so we get खाता है

This pattern is very common in the simple/habitual present:

• masculine singular: -ता है
• feminine singular: -ती है
• masculine plural: -ते हैं
• feminine plural: -ती हैं

So:

• वह पढ़ता है = he studies / he is studying habitually
• वह पढ़ती है = she studies
• वह खाता है = he eats
• वह खाती है = she eats

In most basic grammar explanations, पढ़ती है is the habitual/simple present form, so it usually means studies or reads.

So this clause is most naturally understood as:

• बहन ... पढ़ती है = The sister studies / reads ...

If you specifically wanted is studying right now, Hindi more often uses the progressive:

• पढ़ रही है = is studying / is reading

Likewise:

• खाता है = eats / habitually eats
• खा रहा है = is eating

So this sentence sounds more like a general statement or routine than a description of an action happening at this exact moment.

Hindi normally follows Subject–Object/Other information–Verb order, often described as SOV.

In this sentence:

• बहन = subject
• ऊपर कमरे में = location
• पढ़ती है = verb phrase

And:

• भाई = subject
• नीचे रसोई में = location
• खाता है = verb phrase

So Hindi often puts the verb at the end:

• बहन ऊपर कमरे में पढ़ती है
• भाई नीचे रसोई में खाता है

This is different from English, which usually puts the verb earlier:

• The sister studies upstairs in the room
• The brother eats downstairs in the kitchen

में is a very common postposition meaning in, inside, within, or sometimes at, depending on context.

Here:

• कमरे में = in the room
• रसोई में = in the kitchen

Hindi uses postpositions, not prepositions. That means the word comes after the noun, not before it.

Compare:

• English: in the room
• Hindi: कमरे में

Also notice that the noun often changes form before a postposition:

• कमरा → कमरे में
• रसोई → रसोई में (no visible change here)

Because many Hindi nouns change into an oblique form before a postposition such as में, से, पर, को, etc.

For masculine nouns ending in -ा, the singular oblique form often changes -ा to -े:

• कमरा → कमरे
• लड़का → लड़के
• घर → घर (no change)
• रसोई → रसोई (no change)

So:

• कमरे में = in the room
• लड़के को = to the boy

That is why कमरा में would sound wrong in standard Hindi.

ऊपर means up, above, or upstairs, and नीचे means down, below, or downstairs.

In this sentence they work like location words:

• ऊपर कमरे में = upstairs in the room / in the upstairs room
• नीचे रसोई में = downstairs in the kitchen / in the downstairs kitchen area

These words are very flexible in Hindi. They can act a bit like adverbs and a bit like location markers depending on context.

Examples:

• वह ऊपर है = He/She is upstairs.
• वह नीचे है = He/She is downstairs.
• ऊपर कमरे में = in the room upstairs
• नीचे रसोई में = in the kitchen downstairs

Often, yes—ऊपर के कमरे में can sound more explicit if you want to say in the upstairs room.

Compare:

• ऊपर कमरे में = upstairs in the room / in the room upstairs
• ऊपर के कमरे में = in the upstairs room

The version in your sentence is understandable and fairly natural in context, especially in simple learner-style sentences. But ऊपर के कमरे में makes the relationship between upstairs and room more explicit.

Similarly:

• नीचे रसोई में = downstairs in the kitchen
• नीचे की रसोई में = in the downstairs kitchen

Hindi does not have articles like English a/an/the.

So a noun like बहन can mean:

• a sister
• the sister
• sometimes just sister

The exact meaning depends on context.

Likewise:

• भाई = a brother / the brother
• कमरा = a room / the room
• रसोई = a kitchen / the kitchen

When translating into English, you add a or the based on what sounds natural in the situation.

Hindi often leaves out possessives like my, your, his, etc. when the relationship is obvious from context.

So:

• बहन may mean sister or the sister
• भाई may mean brother or the brother

If you want to be specific, you can add a possessive:

• मेरी बहन ऊपर कमरे में पढ़ती है = My sister studies upstairs in the room.
• मेरा भाई नीचे रसोई में खाता है = My brother eats downstairs in the kitchen.

Without मेरा/मेरी, the sentence is more general or context-dependent.

और means and.

It connects the two clauses:

• बहन ऊपर कमरे में पढ़ती है
• और
• भाई नीचे रसोई में खाता है

So the whole sentence is:

• sister studies upstairs in the room, and brother eats downstairs in the kitchen.

और is one of the most common connector words in Hindi.

Because each half of the sentence has its own full verb phrase.

• पढ़ती है = studies
• खाता है = eats

Hindi often forms the habitual present with:

• main verb stem + ता/ती/ते
  • है/हैं

So each subject gets its own complete verb phrase:

• बहन ... पढ़ती है
• भाई ... खाता है

You cannot usually share just one है across both clauses here, because the two verb forms are separate and agree differently with different subjects.

Because each subject is singular:

• बहन = singular
• भाई = singular

So we use:

• पढ़ती है
• खाता है

If the subjects were plural, you would use हैं:

• बहनें ऊपर कमरे में पढ़ती हैं = The sisters study upstairs in the room.
• भाई नीचे रसोई में खाते हैं = The brothers eat downstairs in the kitchen.

Its basic meaning is eats.

Here:

• भाई नीचे रसोई में खाता है = The brother eats downstairs in the kitchen.

In context, it can suggest has his meal or eats food, but grammatically it is simply the verb खाना in the habitual form:

• खाता है = he eats
• खाती है = she eats
• खाते हैं = they eat / you eat (formal/plural)

Yes, Hindi word order is somewhat flexible, but the usual neutral order keeps the verb near the end.

For example, these are possible depending on emphasis:

• बहन ऊपर कमरे में पढ़ती है।
• ऊपर कमरे में बहन पढ़ती है।
• भाई नीचे रसोई में खाता है।
• नीचे रसोई में भाई खाता है।

But the most neutral, textbook-style order is the one you have:

• subject + place + verb

Changing the order often changes emphasis, not the core meaning.

Sometimes, yes—if the context makes them clear.

Hindi often drops subjects when they are obvious. For example, in a conversation where everyone knows who is being discussed, someone might say:

• ऊपर कमरे में पढ़ती है, और नीचे रसोई में खाता है।

But in a standalone sentence, keeping बहन and भाई makes the meaning clear and natural.

A common transliteration is:

Bahan ūpar kamre meṅ paṛhtī hai, aur bhāī nīche rasoī meṅ khātā hai.

A very simple learner-friendly version could also be written as:

Bahan upar kamre mein padhti hai, aur bhai neeche rasoi mein khata hai.

This is not one single official system—different books transliterate Hindi differently—but all of these help show pronunciation.