Know now when a Hiragana vowel extension!
Like double consonants, prolonged vowels avoid communication problems, as they can generate different meanings from very similar words. For example:
おばさん – Aunt
おばあさん – Grandmother
Hiragana vowel extension
Notice the difference between the two words above? That's right.おばあさん has a prolongation of the vowel あ (a). How does this happen? Whenever a vowel appears after a syllable ending with the same vowel, the same vowel is prolonged.. In the case of おばあさん, we have a prolongation of the vowel あ.
Following this rule, we will have:
おばあさん – Prolongation of the vowel a.
ちいさい – Prolongation of vowel i.
すうき – Prolongation of the vowel u.
せんせい – Prolongation of the vowel e.
おはよう – Prolongation of the vowel o.
Right now you might be wondering: If vowel prolongation occurs with the vowel after a syllable ending with the same vowel, then why せんせい is a prolongation of “e” and おはよう is it an extension of "o"?
Simple. As in the Portuguese language, in the japanese language there are exceptions. The prolongation of the vowel え (e) is done with the vowel い (i), and the prolongation of the vowel お (o) is done with the vowel う (u). But be careful. Not all words with えい or おう are extensions. So get to know the words you use well, listening to a lot of music and watching a lot of anime not to make a fuss.
Another important caveat to make here is regarding the correct pronunciation of extensions like せんせい, おはよう, ありがとう. When it comes to a prolongation, we speak the extended vowel for a second longer. Therefore, the mentioned words are read as follows:
せんせい – withoutsee (Prolongation of e, we speak oe for longer.)
おはよう – ohyoo (Prolongation of o, we speak oo longer.)
ありがとう – arigatoo (Prolongation of o, we speak oo longer.)