जब तक कपड़े सूखे नहीं हों, तब तक तह मत करो।

This is a very common Hindi correlative pattern:

जब तक ... तब तक ...

It literally means something like:

as long as/until ... until then ...

So in this sentence:

जब तक कपड़े सूखे नहीं हों, तब तक तह मत करो।

the first part sets the condition/time limit, and the second part gives the main instruction.

English often does not need both parts, but Hindi very naturally uses both together. The second तब तक is sometimes optional in casual speech, but using it makes the sentence feel complete and balanced.

कपड़े is the plural form of कपड़ा.

• कपड़ा = a cloth / a garment / fabric
• कपड़े = clothes

In everyday Hindi, कपड़े very commonly means clothes as a general category, just like English clothes is normally plural.

So here it means the clothes, not just one piece of clothing.

Because सूखे agrees with कपड़े.

Here, सूखा is being used as an adjective meaning dry. Hindi adjectives change form to match gender and number.

For this adjective:

• सूखा = masculine singular
• सूखे = masculine plural
• सूखी = feminine singular/plural in many contexts

Since कपड़े is masculine plural, the adjective becomes सूखे.

So:

• कपड़ा सूखा है = The cloth is dry.
• कपड़े सूखे हैं = The clothes are dry.

This is one of the most important grammar points in the sentence.

हों is a subjunctive form of होना. After जब तक, Hindi often uses the subjunctive when talking about a condition that must be met before something else happens.

So:

• नहीं हैं would sound more like a plain present statement: are not
• नहीं हों sounds more like are not yet / are not in the required state / are not to the point of being

In instructions like this, Hindi often prefers the subjunctive because the speaker is talking about a condition in relation to a future action.

So the idea is not just the clothes are not dry, but more like:

until the clothes are dry / unless the clothes have become dry enough

It is mainly describing a state: the clothes being dry.

This sentence is built around the adjective सूखे = dry, plus the verb होना.

So the meaning is closer to:

until the clothes are not dry

rather than:

until the clothes have not dried

That said, in real usage the difference is small, because English often prefers a verb like dried, while Hindi can naturally express the same idea with a state adjective.

A more action-focused Hindi version would be:

जब तक कपड़े सूख न जाएँ, तब तक तह मत करो।

That means something like:

Don’t fold the clothes until they have dried.

Both are natural, but the original sentence focuses on the state of being dry.

Yes, this often feels unusual to English speakers.

Hindi commonly expresses until X happens as:

जब तक X नहीं ...

So literally:

• जब तक कपड़े सूखे नहीं हों = until the clothes are not dry

But the real meaning is simply:

until the clothes are dry

This is a normal Hindi pattern, not a logical double negative in the English sense. You should think of जब तक ... नहीं ... as a fixed way to express until.

Similar patterns are very common in Hindi:

• जब तक मैं न आऊँ, इंतज़ार करो।
  Wait until I come.

• जब तक काम पूरा न हो, मत जाओ।
  Don’t go until the work is finished.

So the negative here is expected.

तह means fold, layer, or crease.

In this sentence, it works with करना to express the action to fold.

So:

• तह करना = to fold
• तह मत करो = don’t fold

This is one of those very common Hindi combinations where a noun is used with करना to make a verb-like expression.

You may also hear:

• तह लगाना = to fold

So both of these can be used for folding clothes, though तह करना is perfectly understandable and natural.

Hindi very often forms actions by combining a noun or verbal idea with a light verb such as करना, देना, लेना, or लगाना.

So instead of one simple verb, you often get expressions like:

• साफ करना = to clean
• बंद करना = to close
• तह करना = to fold

This is a completely normal feature of Hindi. So तह मत करो is just the negative imperative form of that expression.

मत is the usual word for a negative command: don’t.

So:

• करो = do
• मत करो = don’t do

In this sentence:

• तह करो = fold
• तह मत करो = don’t fold

This is the normal way to form negative imperatives in Hindi.

Compare:

• बैठो = sit

• मत बैठो = don’t sit

• जाओ = go
• मत जाओ = don’t go

So मत goes with the command form to make it negative.

It is a command in the tum register, so it is:

• normal
• direct
• not especially polite
• not rude by itself, depending on context

It would fit speaking to:

• a friend
• a sibling
• a child
• someone you normally address as तुम

If you wanted other levels:

• तू: तह मत कर
• तुम: तह मत करो
• आप: तह मत कीजिए or तह मत करिए

For example, more polite:

जब तक कपड़े सूखे नहीं हों, तब तक तह मत कीजिए।

Because Hindi often leaves out objects or pronouns when they are obvious from context.

In English, we often say:

Don’t fold them.

In Hindi, once कपड़े has already been mentioned, it is completely natural not to repeat a pronoun. The listener understands that तह मत करो refers to the clothes.

Hindi frequently avoids repeating things that are already clear.

You could make the object more explicit in some situations, but it is usually unnecessary here.

Yes, very often it can be.

You could say:

जब तक कपड़े सूखे नहीं हों, तह मत करो।

This still sounds natural and means the same thing.

Adding तब तक makes the sentence more balanced and slightly more explicit. Many speakers like the full paired pattern:

जब तक ... तब तक ...

So both are fine, but the version with तब तक feels a bit more complete.

Yes. A very common alternative is:

जब तक कपड़े सूख न जाएँ, तब तक तह मत करो।

This version uses सूख जाना, which focuses more directly on the process of drying being completed.

So you can think of the difference roughly like this:

• कपड़े सूखे नहीं हों = the clothes are not dry
• कपड़े सूख n जाएँ = the clothes haven’t dried yet / haven’t become dry

Both are good Hindi, but many learners will hear the सूख न जाएँ type very often in everyday speech.

The adjective and verb form would change to match the singular noun.

For example:

जब तक कपड़ा सूखा न हो, तब तक तह मत करो।

Here:

• कपड़ा = singular masculine
• सूखा = masculine singular
• हो = singular subjunctive form

So the original sentence is a good example of agreement:

• कपड़े → plural
• सूखे → plural agreement
• हों → plural/subjunctive agreement

This kind of matching is very important in Hindi.

The structure is:

जब तक + condition, तब तक + instruction

More specifically:

• जब तक कपड़े सूखे नहीं हों = until the clothes are not dry
• तब तक तह मत करो = until then, don’t fold

Hindi generally places the verb at the end of the clause, so the main action करो comes last.

Also notice that मत comes right before the verb:

• तह मत करो

That placement is very natural in Hindi negative commands.