Long vowels: one more mora

A long vowel is not 'say it longer' — it takes a full extra mora. おばさん (aunt) and おばあさん (grandmother) differ by exactly that.

The five pairs

Click a cell: A = short, B = long vowel.

or use the + on each cell

Minimal pairs in sentences

Two sentences side by side, differing by one sound in the same slot. Tap a card to hear the whole line, tap the highlighted part to hear just that.

Five minimal pairs

Ratio = long duration ÷ short duration.

ShortLongShortLongRatio
おばさん / obasanおばあさん / obaasan660 ms800 ms1.21×
おじさん / ojisanおじいさん / ojiisan680 ms790 ms1.16×
ここ / kokoこうこう / koukou320 ms680 ms2.12×
ゆき / yukiゆうき / yuuki400 ms540 ms1.35×
とる / toruとおる / tooru330 ms450 ms1.36×

How to practise

Where these numbers come from

Same voice and rate; ratio of speech-span durations.

Short words inflate the ratio; longer words approach 1.2.