Arabic/definite Article

In Arabic the definite article is (اَل) "al atta3rif", which is the equivalent to "the" in English. It is added at the beginning of a word.
 * (اَلْبِنتُ) al-bintu The girl
 * (اَلْعَينُ) al-3ainu The eye
 * (اَلْكِتَابُ) al-kitaabu The book

The definite article is always written as (اَل). Notice that the "اَ" has a fat7a and the "ل" does not have a vowel. Due to the "ل" in (ال) not having a vowel, it can assimilate into the following letter. The letters that the "ل" assimilates into are the letters that use the tip of the tongue. Known as (الحروف الشمسية) al-huruf al-shamsiyyah, or The Solar Letters. The letters that do not use the tip of the tongue are not assimilated into. They are known as (الحروف القمرية) al-huruf al-qamariyyah or The Lunar Letters.

The Solar Letters:

ت، ث، د، ذ، ر، ز، س، ش، ص، ض، ط، ظ، ل، ن

The Lunar Letters:

أ، ب، ج، ح، خ، ع، غ، ف، ق، ك، م، ه، و، ي

Examples:
 * (اَلكِتَابُ) al-kitaabu The book. This word has a lunar "ل" due to the following letter not using the tip of the tongue.
 * (اَلسَّيَّارَةُ) as-sayyaratu The car. This word has a solar "ل" due to the following letter using the tip of the tongue. Notice that the "ل" is still written. The following letter also has a shadda to denote the doubling, or gemination.

The "اَ" is pronounced as a hamza when it is the initial letter. However, if there is a vowel from the previous word, the "اَ" becomes silent. Examples:
 * (وَاَلكِتَابُ) written "waal-kitaabu" pronounced "wal-kitabu" And the book. Notice that the vowel on the "و" is the vowel that is pronounced, and the one on the "اَ" is silent. It is difficult to discern due to both vowels being the same.
 * (فِي اَلسَّيَّارَةِ) written "fii as-sayyarati" pronounced "fis-sayyarati" In the car. Here, the "ا" is silent and the vowel pronounced is from the previous word. Notice that it does not affect whether the "ل" is solar or lunar. The particle (فِي) is a preposition. Adding it resulted in changing the final vowel in the word from -u to -i. More on this can be found in the time and place grammar section.