التورتة كانت حلوة، واختي خدت الشمعة وحطتها جنب الطبق.

A natural pronunciation is:

et-torta kānet ḥelwa, w-ekhti khadet esh-sham‘a w-ḥaṭṭetha gamb eṭ-ṭabaʔ

A few helpful notes:

• ج in جنب is usually pronounced g in Egyptian, so gamb
• ق in الطبق is often pronounced as a glottal stop ʔ in Egyptian speech, so ṭabaʔ
• The ال article changes its sound before some letters, so:
  • التورتة sounds like et-torta
  • الشمعة sounds like esh-sham‘a
  • الطبق sounds like eṭ-ṭabaʔ

كانت is used because the sentence is talking about the past.

Without كانت:

التورتة حلوة
means The cake is sweet/nice

With كانت:

التورتة كانت حلوة
means The cake was sweet/nice

Also, كانت is feminine because التورتة is feminine.

Because adjectives in Arabic agree with the noun they describe in gender.

• masculine: حلو
• feminine: حلوة

Since التورتة is treated as a feminine noun, the adjective must also be feminine:

التورتة كانت حلوة

واختي breaks down like this:

• و = and
• اختي = my sister

In Arabic writing, the conjunction و attaches directly to the following word, so it is written as one unit.

Also, in informal Egyptian writing, the hamza is often not written, so you may see:

• أختي
• اختي

Both represent my sister.

Because the -ي at the end is the possessive suffix meaning my.

So:

• أخت / اخت = sister
• أختي / اختي = my sister

This is very common in Arabic:

• بيتي = my house
• أمي = my mother
• أخويا = my brother in Egyptian colloquial

Because this sentence is in Egyptian Arabic, not Modern Standard Arabic.

In MSA, to take is often أخذ.
In Egyptian Arabic, the everyday verb is usually خد.

So:

• MSA-style: أخذت
• Egyptian colloquial: خدت

If you are learning spoken Egyptian, خدت is completely normal and very common.

By itself, خدت can match more than one subject in Egyptian, depending on context.

It can mean:

• I took
• you took
• she took

Here, the subject is stated explicitly right before it:

واختي خدت الشمعة

So the meaning is clearly and my sister took the candle.

This is very common in Egyptian: the verb form alone may be ambiguous, but the subject in the sentence makes it clear.

حطتها can be broken into parts:

• حطّ = put
• -ت = she did
• -ها = it / her, feminine

So حطتها means she put it.

In this sentence, it refers back to الشمعة, which is feminine.

So the structure is basically:

حطّت + ها → حطتها

Because it refers to الشمعة, and شمعة is a feminine noun.

In Arabic, object pronouns reflect the gender of the thing they refer to.

So:

• -ه = him / it for a masculine noun
• -ها = her / it for a feminine noun

Since candle here is feminine, Arabic uses -ها.

جنب means beside, next to, or by.

In Egyptian Arabic, it works a lot like a preposition:

• جنب الطبق = next to the plate
• جنبي = next to me / by my side
• جنبها = next to her / next to it

A very Egyptian pronunciation is gamb.

Because these words begin with sun letters. In Arabic, when ال comes before a sun letter, the l sound is absorbed into the next consonant.

So:

• التورتة is pronounced et-torta
• الشمعة is pronounced esh-sham‘a
• الطبق is pronounced eṭ-ṭabaʔ

This happens in pronunciation, even though the spelling still uses ال.

Because Egyptian Arabic very often uses subject + verb order in everyday speech.

So:

واختي خدت الشمعة
sounds natural and conversational.

Verb-first order is also possible in Arabic in some contexts, but in spoken Egyptian, starting with the subject is extremely common, especially when you want to keep the subject clear or make it the topic of the sentence.