Vowel Contraction in Present Tense

Korean verbs have a stem and an ending. To use the polite present tense, you add -아요 or -어 요. The choice depends on the last vowel in the verb stem. We call this vowel harmony. It is a bit like a dress code for vowels. Bright vowels like ㅏ and ㅗ hang out with -아요. Dark vowels like ㅓ, ㅜ, and ㅣ hang out with -어요. When the verb stem ends in a vowel (no bottom consonant), the two vowels meet. Because Korean hates extra work, they often combine into one syllable. It is a grammar traffic light telling you when to merge lanes. If there is a consonant at the bottom (a 받침), the merge is blocked. The consonant acts like a wall. But without that wall, the vowels are free to dance together.

1. 1Find the verb stem by dropping 다. For 가다, the stem is 가.
2. 2Look at the last vowel. If it is ㅏ or ㅗ, prepare to add -아요.
3. 3If it is anything else, prepare to add -어요.
4. 4Check for a 받침. If there is none, merge the vowels.
5. 5ㅏ + ㅏ = ㅏ. Example: 가 + 아요 becomes 가요.
6. 6ㅗ + ㅏ = ㅘ. Example: 오 + 아요 becomes 와요.
7. 7ㅓ + ㅓ = ㅓ. Example: 서 + 어요 becomes 서요.
8. 8ㅜ + ㅓ = ㅝ. Example: 배우 + 어요 becomes 배워요.
9. 9ㅣ + ㅓ = ㅕ. Example: 마시 + 어요 becomes 마셔요.
10. 10ㅐ + ㅓ = ㅐ. Example: 내 + 어요 becomes 내요.
11. 11하 + 여요 = 해요. This one is a special rebel.

You use this every single day. It is the bread and butter of Korean conversation. Use it when you are ordering a latte at a cafe in Gangnam. Use it when you are asking for directions to the nearest subway station. It is perfect for talking to colleagues, teachers, or people you just met. It strikes the perfect balance between being polite and being friendly. Imagine you are at a job interview. You want to sound professional but not stiff. This is your go-to pattern. It is also the standard for texting friends or posting on social media. If you are describing what you do every day, like "I study Korean" or "I drink coffee," you will use these contracted forms.

Do not try to force a contraction if there is a 받침 (final consonant). If the verb is 먹다 (to eat), the stem is 먹. That ㄱ at the bottom is a bodyguard. It prevents the ㅓ in 먹 and the ㅓ in 어요 from touching. So, it stays 먹어요. Also, avoid these contractions in extremely formal settings like military reports or national news broadcasts. In those cases, you would use the -습니다 ending, which does not contract at all. Think of -습니다 as a tuxedo and -아요/어요 as a nice business-casual outfit. You would not wear a tuxedo to a coffee date, right? Similarly, do not use these contractions if you are trying to be poetic or archaic, as uncontracted forms like 보아요 sound very old-fashioned.

The biggest mistake is being too polite to the vowels. Many beginners say 가아요 instead of 가요. It sounds like you are stuttering slightly. Another classic is forgetting the ㅣ to ㅕ change. People often say 마시어요. While technically understandable, it sounds like you are reading from a dusty textbook. Don't be afraid to squish the sounds together! Another trip-up is ㅗ and ㅜ. Remember that ㅗ is a bright vowel and wants ㅏ. ㅜ is a dark vowel and wants ㅓ. Mixing them up is like wearing one brown shoe and one black shoe. It just looks a bit off. Finally, don't forget that 하다 always turns into 해요. It is the most common verb, so memorize it first.

Let's look at the formal polite form -습니다. For 가다, it is 갑니다. There is no contraction here because the ending is totally different. The -습니다 form is like a rigid robot. It doesn't bend or merge. Vowel contraction only happens in the -아요/어요 world. Also, compare it to the plain form -아/어. This is used with close friends. The contraction rules are exactly the same, but you just drop the 요. So 가요 becomes 가. 마셔요 becomes 마셔. The logic of the vowels merging stays the same regardless of whether you are being polite or casual. It is the vowel's nature to merge, not the politeness level's.