मेरे पास आज का अपॉइंटमेंट है।

मेरे पास literally means near me or with me.

Hindi often expresses possession with this pattern:

X के पास Y है = X has Y

So instead of a direct verb like English have, Hindi very often says something like Y is with X.

So:

मेरे पास अपॉइंटमेंट है
literally: An appointment is with me / near me
natural meaning: I have an appointment

Because पास is a postposition. In Hindi, pronouns usually change form before postpositions.

So you do not say मैं पास in this structure.

You get:

• मेरे पास = with me / I have
• तेरे पास = with you
• उसके पास = with him/her
• हमारे पास = with us

So मेरे is the correct form before पास.

आज का means today's or for today.

It is made of:

• आज = today
• का = a linking word meaning something like of or apostrophe-s

So:

आज का अपॉइंटमेंट = today's appointment / the appointment for today

This is different from just आज, which would simply mean today as a time word.

का/की/के are used to connect one noun to another, often showing possession or association.

Here, आज is being connected to अपॉइंटमेंट:

आज का अपॉइंटमेंट = today's appointment

The form का is used because अपॉइंटमेंट is being treated here as masculine singular.

Very roughly:

• masculine singular: का
• feminine singular: की
• plural or masculine oblique: के

You can, but the meaning changes a little.

• मेरे पास आज अपॉइंटमेंट है = I have an appointment today
• मेरे पास आज का अपॉइंटमेंट है = I have today's appointment / I have an appointment for today

So आज by itself acts more like an adverb: today.
But आज का turns into a phrase that modifies अपॉइंटमेंट: today's appointment.

Because Hindi normally puts the verb near the end of the sentence.

A very common Hindi pattern is:

[time/place/other info] + [main noun phrase] + [verb]

So:

• मेरे पास = with me
• आज का अपॉइंटमेंट = today's appointment
• है = is

That final है is completely normal Hindi word order.

Because this sentence is not built like I am ...

It is built more like:

With me, there is today's appointment.

So the verb is not agreeing with I in the way English learners may expect.
It is part of a possession/existence structure.

Since अपॉइंटमेंट is singular here, the verb is है.

If it were plural, you would normally use हैं.

Hindi does not have articles exactly like English a/an/the.

So a bare noun like अपॉइंटमेंट can mean:

• an appointment
• the appointment

The exact meaning depends on context.

If you want to make it more explicit, Hindi can use एक for one/a, but it is often omitted when it is not necessary.

So English needs an appointment, but Hindi often just says अपॉइंटमेंट.

Yes. अपॉइंटमेंट is a common English loanword in modern Hindi, especially in urban speech.

People often use it for things like:

• a doctor's appointment
• an office appointment
• a scheduled meeting

Hindi does have more native or formal alternatives, but अपॉइंटमेंट is very common in everyday conversation.

It is understandable, but it can sound a bit more like I have today's appointment or I have an appointment booked for today.

If you simply want to say I have an appointment today, many speakers might also say something like:

• आज मेरा अपॉइंटमेंट है
• आज मेरी अपॉइंटमेंट है

The exact wording depends on the speaker and how they treat the gender of अपॉइंटमेंट.

So your sentence is possible, but it has a slightly more possession-based feel because of मेरे पास.

Yes. With English loanwords, gender can vary between speakers and contexts.

In your sentence, the use of का shows that अपॉइंटमेंट is being treated as masculine singular:

आज का अपॉइंटमेंट

But some speakers may treat the same borrowed word differently in other sentences.

The important thing is to keep the agreement consistent inside the sentence.

You would normally make the related words plural:

मेरे पास आज के अपॉइंटमेंट हैं।
or
मेरे पास आज कई अपॉइंटमेंट हैं।

Main changes:

• का → के for masculine plural
• है → हैं for plural

So the singular/plural contrast is:

• आज का अपॉइंटमेंट है = today's appointment is
• आज के अपॉइंटमेंट हैं = today's appointments are