क्या यह कहानी सच है, या यह झूठ है?

At the beginning of a sentence, क्या often marks a yes/no question.

So:

• यह कहानी सच है। = This story is true.
• क्या यह कहानी सच है? = Is this story true?

In your full sentence, क्या introduces the whole question: Is this story true, or is it false?

यह means this.

It appears twice because the sentence has two parallel parts:

• यह कहानी सच है
• यह झूठ है

Literally, this is something like:

• Is this story true, or is this false?

In natural English, we usually would not repeat this, but in Hindi repeating यह makes the two choices clear and balanced.

You may also hear shorter versions where the second यह is omitted if the meaning is obvious.

या means or.

So the structure is:

• X है, या Y है?
• Is it X, or is it Y?

In this sentence:

• सच है = is true
• झूठ है = is false / is a lie

So या connects the two alternatives.

They are opposites:

• सच = truth, true
• झूठ = lie, falsehood, sometimes false in context

In this sentence:

• कहानी सच है = The story is true
• यह झूठ है = It is false / It is a lie

So सच and झूठ can act a bit like nouns in Hindi, but in sentences like this they often translate naturally into English adjectives: true and false.

है is the present-tense form of to be for it/this/he/she in singular contexts.

It appears once in each clause:

• यह कहानी सच है
• यह झूठ है

Hindi often repeats है in each part of a sentence like this, especially when two full clauses are joined by या.

In casual speech, sometimes repetition can be reduced, but the full version is very normal and clear.

कहानी is a feminine noun, but that does not force सच or झूठ to change here.

That is because:

• सच and झूठ are being used as predicate words after the noun
• है does not change for gender in the present tense singular

So:

• यह कहानी सच है
• यह बात सच है

Both are fine.

If you used a clearly gendered adjective like सच्चा / सच्ची, then gender would matter:

• यह कहानी सच्ची है। = This story is true.

That is also correct and very natural.

Yes. That would be a very common way to say Is this story true?

Compare:

• यह कहानी सच है।
• यह कहानी सच्ची है।

Both are correct.

The version with सच्ची uses an adjective that agrees with feminine कहानी.
The version with सच uses a word that works more like truth/true without changing form.

Your original sentence is perfectly natural, but learners should know that सच्ची is also very common with feminine nouns like कहानी.

No, the comma is not required in Hindi.

You can write:

• क्या यह कहानी सच है या यह झूठ है?

That is completely normal.

The comma is just a punctuation choice to make the pause clearer. In everyday Hindi writing, punctuation is often used more flexibly than in English.

The sentence follows a very common Hindi pattern:

• क्या + subject + complement + है, या + subject + complement + है?

Breaking it down:

• क्या = question marker
• यह कहानी = this story
• सच = true
• है = is
• या = or
• यह = this / it
• झूठ = false / a lie
• है = is

Hindi often places the main descriptive word before है.

A simple learner-friendly transliteration is:

kyā yah kahānī sach hai, yā yah jhūṭh hai?

A few pronunciation notes:

• क्या = kyā
• यह is often pronounced closer to yah in careful speech, though in fast speech it may sound more like yeh
• कहानी = kahānī
• सच = sach
• झूठ = jhūṭh
  
  • झ is a voiced aspirated sound, roughly jh
  • ठ is a retroflex ṭh, made with the tongue curled back a bit

Yes.

That is very common in Hindi. Depending on context:

• यह झूठ है can mean This is false
• or This is a lie

In your sentence, since it contrasts with सच है, the natural English meaning is:

• Is this story true, or is it false?

But the nuance or is it a lie? is also possible.