कलम मेज़ पर है, लेकिन कागज़ कहाँ है?

Because Hindi uses postpositions, not prepositions.

• In English, you say on the table.
• In Hindi, you say मेज़ पर = literally table on.

So पर means on, but it comes after the noun it relates to.

A few similar patterns:

• घर में = in the house
• कुर्सी के नीचे = under the chair
• मेज़ पर = on the table

Here पर means on.

So:

• मेज़ पर = on the table

It is a very common location word in Hindi.

In Hindi, the verb usually comes at the end of the sentence or clause.

So:

• कलम मेज़ par है = literally pen table on is
• कागज़ कहाँ है = literally paper where is

This is normal Hindi word order. English and Hindi organize sentences differently.

Hindi usually does not use articles the way English does.

So:

• कलम can mean a pen or the pen
• मेज़ can mean a table or the table
• कागज़ can mean paper, a paper, or sometimes the paper, depending on context

Context tells you which meaning is intended.

If you really want to say one/a, Hindi can use एक, but it is often unnecessary:

• एक कलम = a/one pen

Because each part is its own clause and each clause needs its own verb.

The sentence has two parts:

1. कलम मेज़ पर है = The pen is on the table
2. लेकिन कागज़ कहाँ है? = But where is the paper?

So Hindi repeats है just like English repeats is:

• The pen is... but where is the paper?

लेकिन means but.

It is a very common and standard way to connect two contrasting ideas:

• कलम मेज़ पर है, लेकिन कागज़ कहाँ है?

You may also hear पर used informally to mean but in conversation, but लेकिन is very clear and neutral.

Because कहाँ is the question word where, and in Hindi it usually appears before the verb.

So:

• कागज़ कहाँ है? = literally paper where is?

This is the normal Hindi pattern for many question words:

• वह कौन है? = Who is he/she?
• तुम कहाँ हो? = Where are you?
• यह क्या है? = What is this?

Yes, absolutely.

Both are possible:

• कागज़ कहाँ है?
• कागज़ कहाँ पर है?

The version without पर is very common and natural.
Adding पर makes the location idea a little more explicit, but in many everyday situations it is not necessary.

Yes, they have grammatical gender:

• कलम is usually feminine
• मेज़ is usually feminine
• कागज़ is usually masculine

In this sentence, it does not change है, because है is used for singular subjects regardless of gender.

So both of these are correct:

• कलम ... है
• कागज़ ... है

Gender becomes more visible with adjectives and some verb forms. For example:

• लाल कलम = red pen
• सफ़ेद कागज़ = white paper

Both words contain the letter ज़, which represents a z sound.

• मेज़ sounds roughly like mez
• कागज़ sounds roughly like kaa-gaz

That dot under ज is called a nukta. It changes the sound:

• ज = usually j
• ज़ = z

So:

• मेज would sound different from मेज़
• कागज is often written informally too, but कागज़ shows the pronunciation more accurately

Yes. That is also correct.

Both are natural:

• कलम मेज़ पर है
• मेज़ पर कलम है

The difference is mainly one of focus:

• कलम मेज़ पर है starts with the pen
• मेज़ पर कलम है starts with on the table, so the location is foregrounded more

Hindi word order is somewhat flexible, but the verb usually stays near the end.

In this sentence everything is singular, so Hindi uses है.

If the subject were plural, Hindi would usually use हैं instead:

• कलमें मेज़ पर हैं = The pens are on the table
• कागज़ कहाँ हैं? = Where are the papers?

So:

• singular → है
• plural → हैं

It depends on context.

कागज़ can mean:

• paper as a material
• a paper/document
• a sheet of paper

In a sentence like this, many learners understand it as the paper or the sheet of paper, because the speaker is asking where it is.

So the exact English wording can vary, but the Hindi form stays the same.

No. The comma is mainly a writing choice.

You may see:

• कलम मेज़ पर है, लेकिन कागज़ कहाँ है?
• कलम मेज़ पर है लेकिन कागज़ कहाँ है?

Both are understandable. The comma just helps show the pause before लेकिन.