اختي نسيت المحفظة في البيت امبارح.

Yes. In careful spelling, you may see أختي, but in informal Egyptian writing people often leave the hamza off and write اختي.

It is:

• أخت / اخت = sister
• -ي = my

So اختي means my sister.

Because Arabic often shows possession with a suffix attached directly to the noun.

Here, -ي means my, so:

• أخت = sister
• أختي / اختي = my sister

This is very common in Arabic. You do not need a separate word like English my.

Because in everyday Egyptian Arabic, subject–verb–object order is very common and natural.

So:

• اختي نسيت المحفظة... = My sister forgot the wallet...

If you have studied Modern Standard Arabic, you may have seen more verb-first sentences, but Egyptian often prefers subject-first in ordinary speech.

The subject اختي tells you that.

In Egyptian Arabic, نسيت is a past-tense form, but by itself it can match more than one English subject depending on context. In this sentence, since the subject is my sister, the meaning is she forgot.

So the structure is:

• اختي = my sister
• نسيت = forgot

Together: My sister forgot.

Because Arabic does not usually need an extra pronoun when the subject noun is already stated.

Here, اختي already tells you who did the action, so adding هي would usually be unnecessary unless you want special emphasis.

So اختي نسيت is already complete and natural.

Because الـ makes the noun definite: the wallet.

So:

• محفظة = a wallet / wallet
• المحفظة = the wallet

In this sentence, the speaker is talking about a specific wallet, not just any wallet.

Usually محفظة means wallet in Egyptian Arabic. Depending on context, it can sometimes refer to a small personal holder for money, cards, or papers.

In this sentence, wallet is the most natural meaning.

Because that is a normal Arabic way to express the idea of being at home.

Literally:

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

But in natural English, this is often translated as at home.

Also, Arabic normally uses البيت here, even though English often just says home without the.

امبارح means yesterday.

In Egyptian Arabic, time words are often placed at the end of the sentence, so ... امبارح is very natural.

You can also move it earlier for emphasis, for example:

• امبارح اختي نسيت المحفظة في البيت

But the original order is completely normal.

Yes. Egyptian Arabic has some flexibility with time and place expressions.

For example, you may hear:

• اختي نسيت المحفظة في البيت امبارح
• اختي نسيت المحفظة امبارح في البيت
• امبارح اختي نسيت المحفظة في البيت

These all point to the same basic meaning, though the emphasis may shift slightly. The version you were given sounds natural and everyday.

Because this is Egyptian Arabic, not formal Modern Standard Arabic.

In spoken Egyptian:

• case endings are normally not pronounced
• nouns do not show endings like the ones you may learn in formal grammar

So you understand the sentence mainly from:

• word order
• context
• common usage

That is why المحفظة appears without any special ending marking it as the object.