चाबी बैग में है।

Here is the breakdown:

• चाबी = key
• बैग = bag
• में = in
• है = is

So the sentence is literally structured like:

key bag in is

Natural English: The key is in the bag.

Because Hindi uses postpositions, not prepositions.

• English: in the bag
• Hindi: बैग में = bag in

So में comes after the noun it belongs to.

This is very common in Hindi:

• घर में = in the house
• किताब में = in the book
• बैग में = in the bag

Hindi usually follows Subject–Object/Complement–Verb order, and the verb often comes at the end.

So instead of English:

• The key is in the bag

Hindi says:

• चाबी बैग में है
• literally: Key bag in is

This is normal Hindi sentence structure.

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

So चाबी can mean:

• a key
• the key

And बैग can mean:

• a bag
• the bag

Which one is meant depends on context. In many beginner translations, this sentence is given as The key is in the bag, but Hindi itself does not force that distinction here.

Because चाबी is singular here: one key.

• है = is
• हैं = are

So:

• चाबी बैग में है। = The key is in the bag.
• चाबियाँ बैग में हैं। = The keys are in the bag.

Yes, चाबी is a feminine noun in Hindi.

In this particular sentence, you do not see much effect from that, because है does not change for masculine vs. feminine in the singular present tense.

But gender matters in many other places in Hindi, especially with:

• adjectives
• past participles
• some verb forms

For example, if you used an adjective:

• नई चाबी = new key
  because नई agrees with the feminine noun चाबी.

Yes, absolutely.

Both are natural:

• चाबी बैग में है।
• बैग में चाबी है।

The difference is mostly one of focus or emphasis:

• चाबी बैग में है। → focuses first on the key
• बैग में चाबी है। → starts with in the bag, so it may feel more like “There is a key in the bag” or “The key is in the bag” depending on context

Hindi word order is somewhat flexible, especially in simple sentences like this.

Because it is a loanword from English. Modern Hindi uses many everyday borrowed words, especially for common objects.

So बैग is very normal Hindi usage.

You might also hear other words in different contexts, but बैग is completely natural in speech.

Yes.

• बैग में = in the bag
• बैग के अंदर = inside the bag

में is the normal, simple way to say in.

के अंदर is a bit more explicit, like emphasizing the inside:

• चाबी बैग के अंदर है।

Both are correct, but बैग में is shorter and more common for a basic sentence like this.

A simple pronunciation guide is:

• चाबी ≈ chaa-bee
• बैग ≈ baig / bag with a Hindi-style vowel
• में ≈ mein (nasalized; like mayn with a nasal sound)
• है ≈ hai (like high, but lighter)

Put together:

• chaa-bee baig mein hai

A very rough natural rhythm:

• CHAA-bee BAIG mein hai

बैग में is a location phrase.

It tells you where the key is.

• चाबी = subject/topic
• बैग में = location, “in the bag”
• है = copula, “is”

So the sentence structure is basically:

• [thing] [place] [is]

This pattern is extremely common in Hindi:

• किताब मेज़ पर है। = The book is on the table.
• फोन कमरे में है। = The phone is in the room.
• चाबी बैग में है। = The key is in the bag.