Sokuon っ, Long Vowels, and the Sound and Mora of ん

What You Will Learn in This Unit

Japanese is a language in which each character occupies a unit of sound of equal length called mora (モーラ). In this unit, you will learn how the small character っ occupies one mora, the notation rules for long vowels written by stretching a vowel, and the rules for how the sound of ん changes depending on the following character. You will also check words whose meaning changes depending on vowel length.

The Concept of Mora (モーラ)

A mora is a sound unit in Japanese that is pronounced with the same length. One hiragana character is usually one mora, and a yōon (such as きゃ) is one mora formed by two characters combined. The sokuon っ, long vowels, and ん are each counted as one mora. Therefore, the number of morae may differ from the number of characters. The following table shows the number of morae in words.

きて and きって differ by only one っ, but one more mora is added. Because morae must be read at the same length, きって is read as き, っ, and て at equal length.

The Sound and Notation of the Sokuon っ

The sokuon っ is a small form of つ. It does not produce a sound by itself. Instead, it makes the consonant of the following character pause briefly and then release it with force. Thus っ occupies one mora, and the consonant of the following character is pronounced doubled. Before the て in きって, the t sound is doubled, so it is written as kitte.

The two words differ by only one っ, yet both the number of morae and the meaning are different. きて is the て-form of くる (to come), so it is translated as 'having come,' and きって means a postage stamp.

Long Vowel Notation Rules

A long vowel is a vowel stretched to a length of two morae. A long vowel is written by adding a vowel character determined by the vowel row of the preceding character. The following table summarizes this.

Because a long vowel is written with the vowel character that follows it, there are words whose meaning changes if that character is left out. おばさん(obasan) means aunt or middle-aged woman, while おばあさん(obāsan) means grandmother. The two words have 4 and 5 morae respectively.