Tôi muốn uống nước nữa.

A word-by-word breakdown is:

• Tôi = I
• muốn = want
• uống = drink / to drink
• nước = water
• nữa = more / another / again, depending on context

So the sentence is literally something like:

• I want drink water more

But in natural English, that becomes:

• I want to drink more water
• or I want another drink of water, depending on context.

Vietnamese does not use an infinitive marker like English to in this kind of sentence.

In English:

• I want to drink water.

In Vietnamese:

• Tôi muốn uống nước.

So after muốn (want), you can directly put the verb:

• muốn ăn = want to eat
• muốn đi = want to go
• muốn uống = want to drink

This is very normal Vietnamese grammar.

In this sentence, nữa adds the idea of more, another, or again.

So Tôi muốn uống nước nữa can suggest:

• I want to drink more water
• I want another water/drink
• I want to drink water again / some more

The exact nuance depends on the situation.

For example:

• If you already had some water and want more, nữa means more / some more.
• If you are being offered drinks and want another one, it can feel like another.
• In some contexts, it can also sound like again.

In Vietnamese, words like nữa often come after the thing or action they modify.

So:

• uống nước nữa = drink water more / drink more water

This feels backward from English, but it is normal in Vietnamese.

Compare:

• ăn nữa = eat more
• nói nữa = speak more / keep talking
• uống nước nữa = drink more water

So even though English puts more before water, Vietnamese often puts nữa later in the sentence.

Yes, Tôi muốn uống thêm nước is very natural, and many learners will hear this pattern often.

A simple way to think about it:

• thêm often means more / additional
• nữa often means more / another / again

In many everyday situations, both can work, but the sentence structure changes:

• uống thêm nước = drink more water
• uống nước nữa = drink water more / drink more water

Very roughly:

• thêm often goes before what is added
• nữa often goes after it

So these are both natural:

• Tôi muốn uống thêm nước.
• Tôi muốn uống nước nữa.

If you specifically mean more water, thêm nước can sound especially clear.

No. Nước is a very common Vietnamese word with several meanings depending on context.

It can mean:

• water
• liquid
• drink / beverage in some expressions
• country / nation in other contexts

In uống nước, it usually means water or sometimes a drink depending on the situation.

Examples:

• nước lọc = plain water
• nước cam = orange juice
• đất nước = country

So in your sentence, nước most likely means water, but context is always important.

Yes, it can, depending on context.

Because nước can sometimes be understood more broadly as a drink, the sentence might be interpreted as:

• I want more water
• I want another drink

But if you want to be very specific, Vietnamese often adds another word:

• Tôi muốn uống thêm nước lọc. = I want to drink more plain water.
• Tôi muốn uống thêm một ly nước. = I want another glass of water.
• Tôi muốn uống thứ khác nữa. = I want to drink something else as well.

So the basic sentence is understandable, but context decides the exact meaning.

No. Vietnamese pronouns depend heavily on relationship, age, and social situation.

Tôi is a neutral, fairly safe word for I, especially in textbook Vietnamese. But in real life, speakers often use other pronouns, such as:

• mình
• em
• anh
• chị
• con
• cháu

For example:

• Em muốn uống nước nữa.
• Con muốn uống nước nữa.

These all mean I want more water, but the choice of pronoun changes based on who is speaking and to whom.

So tôi is correct, but not always the most natural choice in casual conversation.

Sometimes, yes.

Vietnamese often drops the subject when it is already clear from context.

So if the situation makes it obvious that you are the one speaking about yourself, you might just say:

• Muốn uống nước nữa.

This can sound natural in conversation, especially in informal speech. However, if you are learning Vietnamese, keeping tôi in the sentence is helpful and clearer.

It is understandable and grammatical, but native speakers might also say it in other common ways.

Some very natural alternatives are:

• Tôi muốn uống thêm nước.
• Tôi muốn thêm nước.
• Cho tôi thêm nước. = Please give me more water.
• Tôi muốn uống thêm một chút nước. = I want to drink a little more water.

Which one sounds best depends on the situation:

• If you are expressing desire: Tôi muốn uống thêm nước.
• If you are requesting more water at a table: Cho tôi thêm nước.

So your sentence is fine, but Vietnamese has several natural variants.

Not by itself.

Vietnamese verbs usually do not change form for tense the way English verbs do. The sentence Tôi muốn uống nước nữa does not explicitly mark past, present, or future. Time is usually understood from context or from time words.

Examples:

• Bây giờ tôi muốn uống nước nữa. = Now I want more water.
• Lát nữa tôi muốn uống nước nữa. = Later I want to drink more water.
• Hôm qua tôi muốn uống nước nữa. = Yesterday I wanted more water.

So muốn stays the same.

A rough learner-friendly guide is:

• Tôi ≈ toy
• muốn ≈ moo-uhn with a rising/broken tone
• uống ≈ oo-uhng with a falling-rising kind of tone
• nước ≈ noo-uhk with a high glottalized tone
• nữa ≈ noo-uh with a similar marked tone

A few important notes:

• Vietnamese is a tonal language, so correct tones matter a lot.
• The vowel combinations in muốn, uống, nước, and nữa are tricky for English speakers.
• A rough English spelling can only help a little; listening to native audio is much better.

Also, Vietnamese pronunciation differs by region, especially between northern and southern accents, so you may hear slightly different real-life pronunciations.