मुझे दूध चाहिए।

Because चाहिए usually takes the person in the dative form, not the plain subject form.

• मैं = I
• मुझे = to me / me

So the structure is closer to:

• To me, milk is needed/wanted

That is why मैं दूध चाहिए is incorrect, but मुझे दूध चाहिए is correct.

In this sentence, चाहिए means something like is needed, is wanted, or is required.

So मुझे दूध चाहिए can mean:

• I want milk
• I need milk

Which English translation sounds best depends on the situation. In everyday Hindi, चाहिए is very commonly used for expressing a need or a request for something.

Both can be translated as I want milk, but they are built differently.

• मुझे दूध चाहिए = I want/need milk

  • very common for stating that you need or want something
  • does not change for the speaker’s gender

• मैं दूध चाहता हूँ / चाहती हूँ = I want milk

  • uses the verb चाहना (to want)
  • changes with the speaker’s gender:
    • चाहता हूँ for a male speaker
    • चाहती हूँ for a female speaker

A learner will hear मुझे ... चाहिए very often in real life.

Because चाहिए itself does not change according to the speaker’s gender in this kind of sentence.

So both a man and a woman can say:

• मुझे दूध चाहिए।

This is different from sentences with चाहता / चाहती, which do show gender.

In standard Hindi, चाहिए normally works by itself in the present tense, so you usually do not add है.

So the normal sentence is:

• मुझे दूध चाहिए।

Not:

• मुझे दूध चाहिए है। ❌

For a learner, it is best to memorize X को / मुझे / तुम्हें / उसे ... चाहिए as a set pattern.

Hindi generally does not use articles like English a and the.

So Hindi simply says:

• मुझे दूध चाहिए।

Depending on context, English might translate this as:

• I want milk
• I want some milk
• I need the milk

Hindi leaves that kind of detail to context much more often than English does.

दूध is masculine.

In this exact sentence, that does not create a visible change, because चाहिए stays the same. But the gender of दूध matters in other places, for example with some adjectives or past-tense forms.

So yes, दूध has a gender, but this sentence does not make it very obvious.

मुझे दूध चाहिए is the normal, neutral word order.

Hindi word order is more flexible than English, so other orders are possible for emphasis, for example:

• दूध मुझे चाहिए। = It’s milk that I want / Milk is what I need.

But for a basic statement, learners should use:

• मुझे दूध चाहिए।

A simple learner-friendly pronunciation is:

• mujhe dūdh chāhiye

A rough English approximation:

• moo-jhay doodh chaa-hee-yeh

A few notes:

• मुझे = mujhe
• दूध = doodh
• चाहिए = chaa-hi-ye

The word चाहिए is usually pronounced as one smooth word, not as separate pieces.

For the negative, put नहीं before चाहिए:

• मुझे दूध नहीं चाहिए। = I do not want/need milk.

For a yes-no question, you can add क्या at the beginning:

• क्या मुझे दूध चाहिए? = Do I need milk?

If you want to ask Do you want milk?, you would usually say:

• क्या आपको दूध चाहिए? = Do you want milk?