Arabic/LearnRW/Tanween

The tanween is an "n" sound added to the end of the word in certain circumstances, usually it functions just like the "a" and "an" in English, indicating an indefinite article. The word tanween literally means marginalize/pushing aside, but usually translated as "nunation", "to 'n'", or "'n'ing"; making an "n" sound.

Tanween is indicated by doubling the short vowel at the end of the word. If a word ends with a "kasra" tashkeel, then the tanween is indicated by writing two "kasra"s (one above the other); same with the "dhamma", you write two dhammas, one beside the other. However, with the "fatHa", you don't only double the "fatHa", but you also add an "Alif" and put the double "fatHa"s on the "alif". (remember, "Alif" is the first letter in the Arabic alphabet). So, we can say there are three types of tanween:
 * fatHa tanween.
 * kasra tanween.
 * dhamma tanween.

Pronunciation
fatHa tanween:  The fatHa tanween is pronounced "en", as in "then", "when", "men", "hen", etc. Even though many native Arabic speakers would use "an" to indicate it, since "a" maps to the "aaaa" sound, "en" is probably more accurate.

kasra tanween:  The kasra tanween is pronounced "in", as in "in", "sin", "fin", "min", etc. Again, some native Arabic speakers might indicate a kasra tanween with an "en", thinking that "e" sounds like the Arabic "yaa" letter ("ii" vowel). This is a mistake that stems from not knowing how native English speakers pronounce the "e" sound.

dhamma tanween:  The dhamma tanween is pronounced as a short "oo" followed by an "n". This sounds like the short "un" in "uno" as pronounced in Spanish, not like the long "oon" in "soon".

tanween at the end of a sentence:  If the tanween is the last thing in the sentence, it's not pronounced. In the case of a fatHa-tanween, the alif is pronounced as a long vowel.

The following pronunciation guide for the case where the tanween falls at the end of a sentence works for all letters in all forms.

Technically, سً should be written as ساً or سًا . ''And بً should be written as باً OR بًا. This is due to stopping (waqf) pronunciation, and spelling rules. Any letter except for ء (hamza) and ة (taa marbooTah), always ends in an alif when it ends in fatHataan ("fatHataan" means "two fatHas").''

Examples
كتاب (k-t-aa-b)

BECOMES

كِتـَابٌ (ki-taa-boon) meaning: a book

كتاب (k-t-aa-b)

BECOMES

كِتـَابٍ (ki-taa-bin) meaning: a book

كتاب (k-t-aa-b)

BECOMES

كِتـَابًا (ki-taa-ban) meaning: a book

كتاب (k-t-aa-b)

BECOMES

كِتـَابْ (ki-taab) meaning: (a) book. Note you have not yet learnt about the sign ending this word. It is called a sukoon. It usually looks like a circle. It goes on top of a letter. In Arabic writing, it indicates the end of a syllable.