If there's one chapter of tajweed that shows up most often when you read the Qur'an, this is it: the rules of noon saakin and tanween. Mastering it makes most of your recitation instantly feel neater.
The ruling depends on which letter comes after it. The 28 Arabic letters split into four groups. Let's go through them one by one.
1. Izhaar (pronounced clearly)
If noon saakin or tanween meets one of the six throat letters (huroof halqi):
hamzah, haa, 'ayn, haa, ghayn, khaa
then it is read clearly and distinctly, with no hum. An example is the reading "min khawf" — the noon is pronounced firmly, then joined straight to the next letter.
2. Idghaam (merged)
If it meets one of the following letters, the noon saakin/tanween is merged into the letter that follows. Idghaam is of two kinds:
- Idghaam bi ghunnah (with a hum) — the letters yaa, noon, meem, waaw (easy to remember with the word yanmu). It merges while humming for about two counts.
- Idghaam bila ghunnah (without a hum) — the letters laam and raa. It merges directly, with no hum.
3. Iqlaab (turned into meem)
Just one letter: baa. When noon saakin or tanween meets the letter baa, the noon sound turns into a meem that is lightly concealed, accompanied by a hum. In the mushaf it's usually marked with a small meem placed above the noon.
4. Ikhfa (concealed)
The rest — the 15 letters other than those above — fall under ikhfa haqiqi. Its reading sits between izhaar and idghaam: the noon sound is concealed (neither fully clear nor fully merged) while humming for about two counts, as the mouth gets ready for the next letter.
An easy way to memorize them
Rather than memorizing the 15 ikhfa letters one by one, just memorize the few:
- The 6 izhaar (halqi) letters.
- The 4 + 2 idghaam letters (yanmu + laam-raa).
- The 1 iqlaab letter (baa).
Everything else is ikhfa. That way, you only need to remember 13 letters, and the rest follow automatically.
Practice with color and real examples
The theory above is quickly forgotten if you don't put it into practice. The way it sticks best: see these rules colored within a verse, hear the examples, then imitate them.