هي ليه مش في الجامعة النهارده؟

هي means she.

In this sentence, it is the subject: she. Egyptian Arabic often starts this kind of sentence with the subject pronoun, so هي ليه مش في الجامعة النهارده؟ is literally something like:

she why not in the الجامعة today?

Natural English: Why isn’t she at the university today?

In Egyptian Arabic, question words do not always have to move to the front the way they often do in English.

So:

• هي ليه مش في الجامعة النهارده؟
• literally: she why not at the university today?

This is a very natural Egyptian Arabic word order.

You may also hear:

• ليه هي مش في الجامعة النهارده؟

That also works, but هي ليه... is extremely common in speech.

So the main point is: Egyptian Arabic is often more flexible than English with question-word position.

ليه means why.

It is the common Egyptian Arabic way to say why in everyday speech.

Examples:

• ليه متأخر؟ = Why are you late?
• ليه مش جاي؟ = Why aren’t you coming?

So in your sentence, ليه is simply asking for the reason.

مش is the negation word here. It means not.

In this sentence, it makes the meaning negative:

• في الجامعة = at the university
• مش في الجامعة = not at the university

So مش is what gives you isn’t / not in the translation.

In Egyptian Arabic, the present-tense verb to be is usually not said in sentences like this.

So Arabic says:

• هي في الجامعة
  literally: she at the university
  meaning: She is at the university

And the negative becomes:

• هي مش في الجامعة
  literally: she not at the university
  meaning: She isn’t at the university

So there is no separate word for is here. The meaning is understood automatically, and مش negates the whole idea.

في usually means in, but in many contexts it is naturally translated as at.

So:

• في البيت = in the house / at home
• في الجامعة = in the university / at the university

In English, at the university sounds more natural here, so that is usually how this sentence is translated.

الجامعة means the university.

The الـ at the beginning is the definite article, the equivalent of the in English.

So:

• جامعة = a university / university
• الجامعة = the university

In this sentence, في الجامعة means at the university.

النهارده means today in Egyptian Arabic.

It is a very common everyday Egyptian word. A learner may also know اليوم, which means today in Modern Standard Arabic, but in spoken Egyptian, النهارده is much more natural.

So:

• النهارده = today

That is a very normal place for a time expression in Egyptian Arabic.

Arabic often puts words like today, tomorrow, now, or yesterday toward the end:

• هي في البيت النهارده = She is at home today
• هو مشغول دلوقتي = He is busy now

So النهارده at the end sounds completely natural.

You would remove مش:

• هي في الجامعة النهارده؟
  = Is she at the university today?

Or as a statement:

• هي في الجامعة النهارده.
  = She is at the university today.

So مش is the key word that makes it negative.

Sometimes yes, if the context already makes it clear who you are talking about.

For example, if everyone already knows you mean one particular woman, someone might say:

• ليه مش في الجامعة النهارده؟
  = Why isn’t she at the university today?

But including هي makes the subject explicit and often sounds clearer, especially for learners.

So:

• هي ليه مش في الجامعة النهارده؟ = clear and natural
• ليه مش في الجامعة النهارده؟ = also possible in context

Although it is written في الجامعة, in fast natural Egyptian speech it is often pronounced something like:

fil-gāmʿa

This happens because:

• في = fi
• الجامعة begins with ال
• together they often sound like fil-...

So learners may see في الجامعة in writing but hear fil-gāmʿa in speech.

A very literal breakdown is:

• هي = she
• ليه = why
• مش = not
• في = in / at
• الجامعة = the university
• النهارده = today

So the literal order is:

She why not at the university today?

Natural English: Why isn’t she at the university today?

This sentence is specifically Egyptian Arabic in its everyday spoken form.

The biggest clues are:

• ليه for why
• مش for negation
• النهارده for today

In Modern Standard Arabic, you would normally use different words, such as:

• لماذا هي ليست في الجامعة اليوم؟

That said, if your goal is spoken Egyptian, هي ليه مش في الجامعة النهارده؟ is exactly the kind of sentence you want to learn.