مرات بنقعد في البيت يوم الاحد ومش بننزل.

Yes. Literally, مرات is the plural of مرة, which means time / occasion. But in Egyptian Arabic, مرات is also very commonly used as an adverb meaning sometimes.

So in this sentence, it is not being used as a counted plural like three times. It simply means sometimes.

In Egyptian Arabic, بـ on the imperfect verb usually marks the present habitual / repeated / general sense.

So:

• بنقعد = we stay / we sit in a habitual or general sense
• بننزل = we go out / go down in a habitual or general sense

This fits the sentence well, because it is talking about something that happens sometimes, not one single event.

It can mean either, depending on context.

The verb قعد originally has the idea of sit, but in Egyptian Arabic it is also very often used to mean stay, remain, or spend time somewhere.

So in بنقعد في البيت, the most natural meaning is we stay at home, not literally we sit in the house.

Because the verb already shows the subject.

In Arabic, verbs are conjugated for person and number, so بنقعد and بننزل already tell you the subject is we. A separate pronoun such as إحنا can be added, but it is not necessary.

For example:

• بنقعد = we stay
• إحنا بنقعد = we stay / we do stay with extra emphasis

Because Arabic normally uses في plus البيت to express that idea.

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

In Arabic, it is very normal to say in the house/home where English would often just say at home. Also, البيت can mean both house and home, depending on context.

So في البيت is a very natural way to say at home.

That is just a difference between the two languages.

Arabic often uses the definite article الـ in places where English does not use the. In this sentence, البيت does not sound overly specific or strange. It is simply the normal expression.

So even though the literal form is the house/home, the natural English meaning is just home or at home.

يوم الاحد means on Sunday.

Arabic often expresses time without needing a separate preposition like English on. So a phrase like يوم الأحد can naturally mean on Sunday.

Also:

• يوم = day
• الأحد = Sunday

So literally it is something like the day Sunday, but naturally it means on Sunday.

In everyday Egyptian speech, الأحد is very often pronounced more like el-ḥadd. In informal writing, you may even see الحد instead.

So this sentence uses colloquial Egyptian grammar, but the spelling of الأحد is a bit closer to the standard spelling. That kind of mixing is very common in informal written Arabic.

Here, مش is the negative word meaning not.

So:

• ومش بننزل = and we don’t go out

Many learners first meet Egyptian verbal negation as ما...ش, so they might expect وما بننزلش. That form is also very common. But مش before the verb is also used by many speakers in everyday Egyptian.

So the important point here is simply that مش is negating بننزل.

The verb نزل literally has the basic idea of go down / descend.

But in Egyptian Arabic, it is very commonly used for going out, especially when talking about leaving the house and heading outside. That is why:

• بننزل can literally suggest we go down
• but in natural context it often means we go out

So مش بننزل here is naturally understood as we don’t go out.

It sounds habitual / general, not like one specific event.

There are two big clues:

• مرات = sometimes
• the verbs have بـ, which often gives a habitual or regular-present meaning in Egyptian Arabic

So the sentence is describing something that happens from time to time, not one particular Sunday in the past.

It is mostly Egyptian Arabic, especially because of things like:

• مرات
• the بـ present marker in بنقعد and بننزل
• مش as negation

But the spelling الأحد is more standard-looking than what you might see in very casual Egyptian writing. In real life, written Arabic often mixes Egyptian grammar and vocabulary with standard spelling conventions. That is very normal.