The Arabic alphabet contains 28 letters, all of which represent consonants or, in a few cases, long vowels. Short vowels are not part of the alphabet itself but are instead marked through optional diacritics placed above or below the letters. The first letter is alif (ألف), which represents the glottal stop or a long 'a' sound, and it forms the basis of the definite article 'al-'. The second letter is baa' (ب), corresponding to the English 'b' sound, written with a single dot below its curved base. The third letter is taa' (ت), which matches the English 't' sound and is written with three dots above the same base shape as baa'.
The fourth letter is tha (ث), pronounced like the 'th' in 'think', and it looks like baa' but with three dots above instead of one. The fifth letter is jeem (ج), pronounced like the English 'j' in 'jam', and the sixth is haa' (ح), a strong, breathy 'h' from the back of the throat. The seventh is khaa' (خ), a rough guttural sound similar to the Scottish 'ch' in 'loch'. These connector letters flow into words and link with neighboring characters.
Among the consonants, two pairs deserve special attention. The letter thaal (ذ) corresponds to the English 'th' in 'this' or 'that', and it is the ninth letter of the alphabet. Arabic also distinguishes between sun letters and moon letters, each containing 14 consonants. When the definite article 'al-' is attached to a sun letter, the 'l' sound assimilates into that letter, as in ash-shams (الشمس, the sun). With moon letters, however, the 'l' remains clearly audible, as in al-qamar (القمر, the moon), and alif is the first of these moon letters.
A final important letter form is the taa' marbuta' (ة), a special variant of 't' that appears at the end of words to mark femininity. It is pronounced as 'a' in most contexts and as 'at' when the word is in a construct state. Together, these letters and rules form the building blocks of Arabic spelling and pronunciation.