Nūn sākina and tanwīn

Before the six throat letters, say the n clearly, without a nasal hold.

Before the letters of يَرْمَلُونَ, the n merges into the next letter. With ي ن م و, keep a nasal sound (ghunna) for two counts; with ل and ر, merge without one. Inside a single word, such as دُنْيَا, the n stays clear.

Before bāʾ, the n turns into a mīm, held with a ghunna behind lightly closed lips. The muṣḥaf shows a small mīm (ۢ) as a reminder.

Before the other 15 letters, the n is hidden: the tongue doesn’t press, and the sound passes through the nose for two counts while the mouth gets ready for the next letter.