मुझे एक कप चाय दीजिए।

Because मुझे means to me / me, while मैं means I.

In this sentence, the speaker is not the subject doing the action; they are the person receiving something. Hindi often uses मुझे for this kind of to me idea:

• मुझे पानी दीजिए = Please give me water.
• मुझे किताब दीजिए = Please give me the book.

So मुझे is the correct form here, not मैं.

Literally, एक कप चाय is one cup tea.

Hindi often does not need a separate word for English of in expressions like this. So:

• एक कप चाय = a cup of tea
• एक गिलास पानी = a glass of water
• एक प्लेट खाना = a plate of food

English requires of, but Hindi usually just puts the container/measure word before the noun.

दीजिए is a polite imperative form of देना (to give). It means something like:

• please give
• kindly give

So the sentence is a polite request, not just a plain command.

Compare:

• दो = give (informal)
• दीजिए = please give (polite)
• दीजिये = same pronunciation; an alternative spelling you may also see

In everyday Hindi, दीजिए is a very common polite form when asking for something.

It is polite and appropriate in many everyday situations, such as speaking to:

• a waiter
• a shopkeeper
• an older person
• someone you want to address respectfully

It is more polite than मुझे एक cup चाय दो and less elaborate than very formal phrasing.

If you want to be even softer, you could also say:

• मुझे एक कप चाय दीजिए, कृपया।
• कृपया मुझे एक कप चाय दीजिए।

But in normal speech, दीजिए already sounds polite.

Grammatically, it is an imperative, but in actual use it functions as a polite request.

So although the verb form is technically a command form, दीजिए is often understood as:

• Please give me...
• Could I have...

In many service situations, Hindi uses this structure naturally for requests.

Yes. Hindi word order is flexible, although some orders sound more neutral than others.

The most natural neutral order here is:

• मुझे एक कप चाय दीजिए।

But you may also hear:

• एक कप चाय मुझे दीजिए।
• मुझे चाय का एक कप दीजिए।

These are still understandable, but the first version is the most straightforward and common for learners to use.

Yes, you can say चाय का एक cup or more fully चाय का एक कप, and it means essentially the same thing: a cup of tea.

However, एक कप चाय is usually simpler and very common in everyday speech.

So both are possible, but:

• एक कप चाय = very common and natural
• चाय का एक कप = also correct, a bit more explicitly structured

In this sentence, there is no obvious agreement change to notice.

A few points:

• एक stays एक regardless of gender here.
• चाय is feminine, but there is no adjective here that needs to change form.
• दीजिए is a polite imperative, and it does not change to match चाय in the way a past-tense verb sometimes would.

So even though चाय is feminine, the sentence still remains:

• मुझे एक कप चाय दीजिए।

A rough pronunciation guide is:

mujhe ek kap chai dijiye

A slightly more detailed breakdown:

• मुझे = mu-jhe
  The झ/ज्ह-like sound here is often hard for beginners; many learners approximate it as moo-jhay or mujh-eh.
• एक = ek
• कप = kup or kap
• चाय = chaay
• दीजिए = dee-jee-ye

Natural rhythm: mujhe ek kap chai dijiye

Yes, it is natural and commonly understood.

You could say:

• मुझे एक कप चाय दीजिए।

That works well in a restaurant, at someone’s home, or at a tea stall.

Another common pattern is:

• एक कप चाय दीजिए।
  This leaves out मुझे and is also very natural.

If you want to sound slightly less direct, you might also hear:

• मुझे एक कप चाय चाहिए। = I want / I need a cup of tea.

But for ordering, दीजिए is extremely common and useful.

They are just spelling variants of the same word. Both represent the same polite imperative form.

You may see:

• दीजिए
• दीजिये

In modern standard writing, दीजिए is often preferred, but both are widely recognized.

So if you encounter either one, the meaning is the same.

Yes, if the exact number is not important.

Compare:

• मुझे एक कप चाय दीजिए। = Please give me one cup of tea.
• मुझे कप चाय दीजिए। = not natural
• मुझे चाय दीजिए। = Please give me tea.

If you want a cup of tea, keeping एक कप is best. If you simply want tea, then मुझे चाय दीजिए is natural.

So you usually either say:

• मुझे एक कप चाय दीजिए or
• मुझे चाय दीजिए

but not normally मुझे कप चाय दीजिए.

The dictionary form is देना, which means to give.

Here is the relationship:

• देना = to give
• दो = give! (informal)
• दीजिए = please give! (polite)

So दीजिए is a polite imperative form built from the verb देना.

Sometimes in context, yes, but literally it is Give me a cup of tea.

In English, bring me and give me can overlap in service situations. In Hindi, दीजिए is from देना (to give), so the literal idea is give.

If you specifically want bring, Hindi would use a form of लाना:

• मेरे लिए एक कप चाय लाइए। = Please bring a cup of tea for me.

But in many real situations, मुझे एक कप चाय दीजिए is the normal and natural thing to say when ordering tea.