Vowels Shrink Naturally When They Meet

When a verb or adjective stem ends in a vowel, adding -아요 or -어요 puts two vowels right next to each other.

Instead of pronouncing both vowels slowly and separately, Korean speakers naturally blend them together. This isn't a complex list of separate math formulas to memorize. It is simply the natural result of saying the words at a normal speaking speed.

Here is how common words naturally shrink when they meet -아요 or -어요 . Notice how the pronunciation smoothly glides from the stem into the ending.

Natural Merges

Dictionary Form · Stem + Ending · Natural Merged Form

가다 · 가 + 아요 · 가요

서다 · 서 + 어요 · 서요

보다 · 보 + 아요 · 봐요

오다 · 오 + 아요 · 와요

배우다 · 배우 + 어요 · 배워요

마시다 · 마시 + 어요 · 마셔요

기다리다 · 기다리 + 어요 · 기다려요

되다 · 되 + 어요 · 돼요

Try saying 보아요 faster and faster. You will notice your mouth naturally forms 봐요 .

The same happens with 마시어요 . As you speed up, 시어 glides into 셔 , creating 마셔요 .

You do not need to memorize these as strict mathematical rules. Let your mouth do the work. If the stem has no final consonant, expect the vowels to merge.

When writing, beginners sometimes try to keep the full vowel ending even after the stem has already absorbed it.

For example, 가다 plus 아요 becomes 가요 . It is incorrect to write 가아요 . The 아 sound is already merged into 가 .

Similarly, 보다 becomes 봐요 . Writing 봐아요 is a common mistake. Once the vowels have merged into a shorter block, you do not add another -아요 or -어요 .

Watch out: Avoid adding extra vowels