जब तक वॉश साइकल खत्म नहीं हो, तब तक इंतज़ार कीजिए।

This is a common correlative pair in Hindi.

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

So the pattern is:

जब तक X, तब तक Y
= Until X happens, do Y

In your sentence:

जब तक वॉश साइकल खत्म नहीं हो, तब तक इंतज़ार कीजिए।
= Until the wash cycle is finished, wait.

Hindi often likes this matching structure. In casual speech, people may sometimes omit the second part, but using both sounds clear and natural.

This is one of the most common things that surprises English speakers.

In Hindi, जब तक often works with a negative verb:

• जब तक ... नहीं ...
• literally: until ... not ...
• natural English: until ...

So:

जब तक वॉश साइकल खत्म नहीं ho
literally = until the wash cycle is not finished
natural meaning = until the wash cycle is finished

This is normal Hindi usage. It is not a mistake.

A similar pattern appears in many sentences, for example:

• जब तक मैं न कहूँ, शुरू मत कीजिए।
  = Don’t begin until I say so.

खत्म means finished / over / ended.
With होना, it forms the idea to become finished or to end.

So:

• खत्म होना = to finish / to be over
• वॉश साइकल खत्म हो = the wash cycle finishes / becomes finished

This is a very common Hindi structure:

• काम खत्म हो गया = the work got finished
• फिल्म खत्म हो गई = the movie ended

So in your sentence, Hindi is not using a single verb meaning to finish. It is using the expression खत्म होना.

Here हो is the subjunctive form of होना. After words like जब तक, Hindi often uses this kind of form.

So:

• हो here does not mean a command
• it is part of a subordinate clause: until it be finished / until it finishes

Why not the others?

• है would sound wrong here because that is a present indicative form.
• हुआ is a past/perfect form, so it would not fit this structure.
• हो जाए is possible in some contexts, but it adds a slightly different nuance, often suggesting gets done / comes to completion. Your sentence is simpler and more neutral.

So खत्म नहीं हो is a normal and natural way to say until it is finished.

In Hindi, नहीं usually comes before the verb element it is negating. In a phrase like खत्म होना, the verbal part is होना, so नहीं often appears before हो:

• खत्म नहीं हो
• शुरू नहीं हुआ
• बंद नहीं है

So खत्म नहीं हो is the expected order.

You may sometimes hear other placements for emphasis in speech, but for a learner, खत्म नहीं हो is the pattern to remember.

इंतज़ार is a noun meaning waiting or expectation, and Hindi commonly combines such nouns with करना to make a verbal expression.

So:

• इंतज़ार करना = to wait

When you make it a polite command, करना becomes कीजिए:

• इंतज़ार कीजिए = please wait

This kind of noun + करना combination is very common in Hindi:

• फ़ैसला करना = to decide
• कोशिश करना = to try
• सफ़र करना = to travel

So although English uses the simple verb wait, Hindi uses the expression इंतज़ार करना.

कीजिए is a polite imperative used with आप.

So:

• इंतज़ार कीजिए = polite / respectful please wait
• इंतज़ार करो = informal, used with तुम
• इंतज़ार कर = very informal, used with तू

So this sentence is addressing someone politely, which makes sense for instructions, announcements, customer service, or formal situations.

You may also hear:

• इंतज़ार करिए
• इंतज़ार करें

These are also polite. कीजिए sounds very standard and respectful.

Modern Hindi uses many borrowed English words, especially for technology, appliances, and everyday urban life.

So वॉश साइकल is a natural borrowed expression for wash cycle.

A more formal or technical Hindi phrasing might use something more like:

• धुलाई चक्र

But in everyday speech, especially in cities or appliance-related contexts, वॉश साइकल sounds completely normal.

This kind of mixing is extremely common in Hindi.

Yes, the given word order is natural, but Hindi has other natural options too.

The sentence puts the until-clause first:

जब तक वॉश साइकल खत्म नहीं हो, तब तक इंतज़ार कीजिए।

That is very common in Hindi. But another natural version would be:

वॉश साइकल खत्म होने तक इंतज़ार कीजिए।
= Wait until the wash cycle is finished.

This version uses खत्म होने तक instead of जब तक ... तब तक.

So both are possible:

• जब तक ... तब तक ... = a full correlative structure
• ... होने तक = a more compact structure

खत्म is generally used as an indeclinable adjective/adjectival element, so it usually stays the same.

For example:

• काम खत्म है
• फिल्म खत्म है
• किताबें खत्म हैं

The word खत्म itself does not usually change the way many Hindi adjectives do.

Also, in your sentence, हो is a subjunctive form and does not show gender distinction here. So there is no visible feminine marking even if साइकल is treated as feminine.

Yes, that is very close to the literal Hindi logic.

Because of the जब तक ... नहीं ... structure, the sense is:

• for as long as the wash cycle is not finished, wait
• which in natural English becomes:
• wait until the wash cycle is finished

So the sentence combines both ideas:

1. during the unfinished period, wait
2. stop waiting once it has finished

That is why जब तक ... तब तक ... works so well here.

Yes, people could definitely say this, especially in a polite or instructional context.

It sounds suitable for:

• a machine instruction
• a staff announcement
• a polite spoken instruction
• a written notice

In very casual conversation, a speaker might say something shorter, like:

• वॉश साइकल खत्म होने तक इंतज़ार करो।
• साइकल खत्म होने तक रुको।

So your sentence is natural, polite, and slightly formal—very appropriate for standard Hindi.