आज बारिश हो रही है, और मैं घर में हिंदी पढ़ रही हूँ।

Hindi usually does not need a dummy subject like English it in weather expressions.

So English: It is raining.

becomes Hindi: बारिश हो रही है।

Literally, this is closer to: Rain is happening.

That is a very normal Hindi way to express weather. The word बारिश means rain or rainfall, and हो रही है means is happening / is occurring.

हो रही है is a present progressive form, meaning is happening or is taking place.

It is made from:

• हो
  • from the verb होना (to be / to happen)
• रही
  • progressive marker agreeing with a feminine singular subject
• है
  • is

In बारिश हो रही है, the subject is बारिश, which is a feminine singular noun, so Hindi uses रही.

Because बारिश is a feminine singular noun.

In Hindi, the progressive participle often agrees with the subject in sentences like this. So:

• masculine singular: रहा
• feminine singular: रही
• plural: रहे

Since बारिश is feminine singular, you get: बारिश ho रही है

If the noun were masculine singular, you would expect रहा instead.

Yes. पढ़ रही हूँ shows that the speaker is female.

Breakdown:

• पढ़
  • study/read
• रही
  • progressive feminine singular
• हूँ
  • am

So मैं हिंदी पढ़ रही हूँ means I am studying/reading Hindi, said by a female speaker.

If the speaker were male, it would be: मैं हिंदी पढ़ रहा हूँ।

It can mean either, depending on context.

In this sentence, मैं घर में हिंदी पढ़ रही हूँ most naturally means:

• I am studying Hindi at home, or
• I am reading Hindi at home

If the person is a learner, studying Hindi is probably the intended meaning. Hindi पढ़ना is often used for both read and study, so context matters.

Hindi word order is usually Subject - Object - Verb.

So:

• मैं = I
• हिंदी = Hindi
• पढ़ रही हूँ = am studying/am reading

That gives: मैं हिंदी पढ़ रही हूँ।

In English, the order is also often I + study + Hindi, but Hindi places the verb at the end more consistently.

घर में literally means in the house / in the home.

• घर = home/house
• में = in

But in natural English, this phrase is often translated as at home, because that sounds more idiomatic.

So: मैं घर में हिंदी पढ़ रही हूँ can be understood as I am studying Hindi at home.

में is a postposition meaning in.

Hindi uses postpositions instead of English-style prepositions. That means the word comes after the noun, not before it.

So:

• English: in the house
• Hindi: घर में literally house in

This is a very common Hindi pattern.

और means and.

It connects the two parts:

• आज बारिश हो रही है
• मैं घर में हिंदी पढ़ रही हूँ

So the full sentence is: Today it is raining, and I am studying Hindi at home.

आज means today, and placing it at the beginning is very natural in Hindi.

Hindi is fairly flexible with adverbs of time, but putting आज first clearly sets the time frame for the whole sentence: आज बारिश हो रही है, और मैं घर में हिंदी पढ़ रही हूँ।

This is like saying: Today, it is raining, and I am studying Hindi at home.

Because they agree with different subjects.

• है goes with बारिश (rain) as a third-person singular subject.
• हूँ goes with मैं (I) as a first-person singular subject.

So:

• बारिश हो रही है = Rain is happening / It is raining
• मैं पढ़ रही हूँ = I am studying

This is normal subject-verb agreement in Hindi.

Sometimes yes, because Hindi often drops pronouns when the meaning is clear from context.

So in conversation, someone might say: आज बारिश हो रही है, और घर में हिंदी पढ़ रही हूँ।

Because पढ़ रही हूँ already shows I am and also suggests a female speaker, the listener may understand the subject without मैं.

However, including मैं is completely natural and clearer for learners.

The comma is mainly a writing choice to separate the two clauses. It is not essential to Hindi grammar.

You could write: आज बारिश हो रही है और मैं घर में हिंदी पढ़ रही हूँ।

That is also correct.

The comma just helps readability, especially in a longer sentence with two linked ideas.