The mora nasal is noted by ん ( n ） in kana. It is a nasal sound not necessarily pronounced the same way every time. For native languages of many Japanese language learners, the nasal such as [n] is pronounced as [n] no matter what comes after it. However, this is not the case for the Japanese mora nasal. That is to say, the pronunciation of the mora nasal in Japanese varies according to the consonant that follows it. If vowels of the a-row or semi-vowels of the ya( ヤ )-column and wa( ワ )-column follow the mora nasal, then the mora nasal would sound like a vowel with a nasal sound. For example, the mora nasal in ren'ai ( れんあい（恋愛） love), tan'i ( たんい（単位） a unit),denwa ( でんわ（電話） telephone) or hon'ya( ほんや（本屋）bookstore) would be pronounced similar to a nasalized vowel.
When the mora nasal appears at the end of a word or sentence or is followed by sounds from the sa ( サ ) and ha ( ハ )-columns, then there are many cases where the tongue is positioned more to the back then when pronouncing [ŋ]. Practice saying un, while drawing in the chin and nod. It is similar to this sound. After remembering the position of the tongue, practice the above-mentioned way and try sayingpen( ペンpen).
Pay attention to the fact that native Japanese speakers perceive the mora nasal as having the same duration as a mora. In the case of pen ( ペン ), although some learners perceive it as one unit, native Japanese speakers would perceive it as pe-n ( ペ・ン ) with two moras. Practice pronouncing the mora nasal and pe with the same duration.