जब तक दाग़ साफ नहीं हो, तब तक कपड़ा भिगोकर रखिए।

This is a very common Hindi correlative structure:

• जब तक = until / as long as
• तब तक = until then / for that long

So the pattern is:

जब तक X, तब तक Y
= Until X, do Y

In this sentence, it sets up a time limit: keep doing one thing up to the point when something else happens.

Hindi often uses both parts together, even though English usually just says until once.

This is one of the most important things to notice in Hindi.

With जब तक, Hindi very often uses नहीं even when English would not. So:

जब तक ... नहीं ...
often means
until ...

So जब तक दाग़ साफ नहीं ho does not mean as long as the stain is not clean in a clumsy literal sense. Idiomatically, it means:

• until the stain is clean
• until the stain comes out
• until the stain is gone

This is normal Hindi usage, not a logical double negative.

A similar example:

• जब तक बारिश बंद नहीं हो, तब तक बाहर मत जाइए। = Don’t go outside until the rain stops.

हो is a form of होना (to be / to become). Here it is the subjunctive form, which is very common after words like:

• जब तक = until
• अगर = if
• चाहे = whether/even if
• ताकि = so that

So साफ नहीं हो means something like:

• is not clean
• does not become clean
• has not come clean yet

In natural English for this sentence, the best sense is usually becomes clean or comes out.

Yes.

The structure is:

• दाग़ = stain
• साफ = clean
• हो = become / be

So literally the clause is something like:

until the stain becomes clean

That may sound odd in English, but it is a natural Hindi way to express until the stain comes out or until the stain is clean.

भिगोकर comes from भिगोना (to soak / to wet thoroughly) plus -कर.

This -कर form often means:

• having done
• after doing
• by doing

So भिगोकर literally means:

• having soaked
• after soaking
• by soaking

But in this sentence, because it is followed by रखिए, the combined meaning is more natural as:

• keep it soaked

So don’t translate it too mechanically as having soaked every time. Here it is part of a larger expression.

Because भिगोकर रखिए means keep it in a soaked state, not just soak it once.

Compare:

• कपड़ा भिगोइए = Soak the cloth
• कपड़ा भिगोकर रखिए = Keep the cloth soaked

This is a very useful Hindi pattern:

[verb]-कर रखना
= to do something and keep it that way

For example:

• दरवाज़ा खोलिए = Open the door
• दरवाज़ा खोलकर रखिए = Keep the door open

So here रखिए adds the idea of continuing the result.

रखिए is the polite imperative form of रखना (to keep / to place).

It is used here because the sentence is giving an instruction politely, like directions on cleaning something.

So the tone is:

• respectful
• polite
• instructional

Other possible levels would be:

• रखो = less polite / familiar
• रखिए = polite
• रखें = also polite, often seen in formal instructions

So रखिए is very natural in advice or instructions.

Because Hindi often leaves out को with inanimate direct objects, especially when they are being mentioned in a general or neutral way.

So:

• कपड़ा भिगोकर रखिए = perfectly natural

Using को is not impossible, but it would usually sound more marked or specific:

• कपड़े को भिगोकर रखिए

That might be used if you were emphasizing that particular cloth. In ordinary instructions, the simpler कपड़ा is more natural.

Some Hindi adjectives change form, but many do not.

साफ is one of the adjectives that usually stays the same. It does not change here for gender or number.

So you can have:

• कपड़ा साफ है
• कमीज़ साफ है
• कपड़े साफ हैं

In all of these, साफ stays साफ.

That is normal.

Yes, sometimes it can be omitted if the meaning is already clear.

For example:

• जब तक दाग़ साफ नहीं हो, कपड़ा भिगोकर रखिए।

This still makes sense.

But using both parts:

• जब तक ... तब तक ...

sounds especially complete, balanced, and natural. It clearly marks the two-part relationship:

• until this happens
• keep doing that until then

So in careful or instructional Hindi, keeping तब तक is very common.

Yes. A very natural alternative is:

जब तक दाग़ साफ न हो जाए, तब तक कपड़ा भिगोकर रखिए।

This version adds a slightly stronger sense of completion:

• until the stain gets cleaned completely
• until the stain comes out

The original साफ नहीं हो is also correct and natural.
The हो जाए version just makes the “become fully clean” idea a bit more explicit.

A rough word-by-word breakdown is:

• जब तक = until / as long as
• दाग़ = stain
• साफ = clean
• नहीं = not
• हो = be / become
• तब तक = until then / for that long
• कपड़ा = cloth
• भिगोकर = having soaked / by soaking
• रखिए = keep (polite)

Very literally, the structure is something like:

Until the stain not become clean, until then keep the cloth soaked.

That is not good English, of course, but it shows how the Hindi pieces fit together. Natural English would be something like:

Keep the cloth soaked until the stain comes out.

Yes, very normal.

Hindi often puts the condition or time clause first, especially with pairs like जब तक ... तब तक.

So this order feels natural:

• जब तक दाग़ साफ नहीं हो, तब तक कपड़ा भिगोकर रखिए।

It matches the logic:

1. first say the limit or condition
2. then say what to do until that point

This is a common and very useful pattern in everyday Hindi.