בינתיים אני רוצה רק מים.

Hebrew word order is fairly flexible, and it is very common to put a time word or time phrase first. Starting with בינתיים sets the frame right away: for now...

So בינתיים אני רוצה רק מים sounds very natural.

If you move it, the sentence can still be understood, but the emphasis changes a little:

• בינתיים אני רוצה רק מים = For now, I only want water
• אני רוצה רק מים בינתיים = I only want water for now

A simple transliteration is:

beintayim ani rotze rak mayim — if a man is speaking
beintayim ani rotza rak mayim — if a woman is speaking

The spelling stays the same in ordinary Hebrew writing.

In normal Hebrew writing, vowels are usually not written. So רוצה can represent two different spoken forms:

• רוֹצֶה / rotze = masculine singular
• רוֹצָה / rotza = feminine singular

With אני, both are possible. The speaker's gender tells you which pronunciation is correct.

Sometimes Hebrew does leave subject pronouns out, but here אני helps a lot because רוצה in the present tense does not show person.

By itself, רוצה could mean:

• I want
• you want
• he wants
• she wants

So אני makes the subject clear. In context, a speaker might drop it, but the full sentence with אני is the safest and most standard form.

Because את is used only before a definite direct object.

Here, מים means water in a general sense, not the water, so you do not use את.

Compare:

• אני רוצה מים = I want water
• אני רוצה את המים = I want the water

So in your sentence, no את is needed.

Because the sentence is talking about water in general, not a specific known water.

Hebrew often treats mass nouns like English does here:

• מים = water
• המים = the water

So:

• רק מים = only water
• רק המים = only the water

If you were referring to a specific glass, bottle, or water already mentioned, then המים could make sense.

Yes, מים has a historically plural or dual-looking form, but in modern Hebrew it is simply the normal word for water.

There is no everyday singular form that people normally use for basic water. So learners just have to remember מים as the standard word.

Because it is grammatically plural, it often takes plural agreement:

• מים קרים = cold water

So even though English treats water as a mass noun, Hebrew uses the fixed form מים.

Here רק is directly before מים, so it means only water.

Word placement matters in Hebrew, just as it does in English. For example:

• אני רוצה רק מים = I want only water
• אני רק רוצה מים = I just want water / all I want is water
• רק אני רוצה מים = Only I want water

So in your sentence, רק clearly limits the thing wanted: water, and nothing else.

אני רוצה is very common and completely correct in everyday Israeli Hebrew. Still, in some situations it can sound a little direct, especially with strangers or in restaurants.

A more polite version could be:

• בינתיים אני רוצה רק מים, בבקשה. = For now I only want water, please.
• אפשר רק מים בינתיים? = Can I have just water for now?

So the original sentence is natural, but politeness depends on context.