Korean: 르 irregular

Irregularities

Most Korean adjectives and verbs follow the basic rules of variation, such as 아/어요, but some exceptions exist, and these exceptions are irregular variations.
Common irregular variations are

• 으 irregular
• ㄹ irregular
• ㅂ irregular
• ㅅ irregular
• ㄷ irregular
• 르 irregular
• ㅎ irregular

This article introduces the use of 르 irregular.

르 irregular

Some adjectives and verbs have a stem that ends in 르 (e.g. 모르다, 부르다) and is followed by a ㅇ (e.g. 아/어요), the stem changes.
This change is called the 르 irregularity.
Below, we introduce the ㅂ니다 form, the 요 form, and the past tense variation.

ㅂ니다形

Same as the normal rules.
ex: 모르다 -> 모릅니다。

요形

Varies according to the vowel of the preceding syllable of the 르 syllable.

1. When the vowel is "ㅏ,ㅗ

The basic rule is that if the vowel is "ㅏ,ㅗ", 아요 is added at the end.
For the 르 irregular, replace the 르 with ㄹ라 and add 요 at the end.
For example, 모르다 -> 몰라요.

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2. When the vowel is other than "ㅏ,ㅗ

The basic rule is that when the vowel is other than "ㅏ,ㅗ", 어요 is added after it.
For the 르 variant, replace the 르 with ㄹ러 and add 요 at the end.
For example, 부르다 -> 불러요.

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3. Exceptions

따르다, 들르다, 지르다 are to be used live according to the 르 variant.
따르다 → 따라요
들르다 → 들러요
지르다 → 질러요

Past tense

The variation rule is similar to the 요-type.

1. When the vowel is "ㅏ,ㅗ

In the case of 르 irregular, replace the 르 with ㄹ라 and add ㅆ다 at the end.
For example, 모르다 -> 몰라요 -> 몰랐어요.

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2. When the vowel is other than "ㅏ,ㅗ

For the 으 irregular, replace the 르 with ㄹ라 and add ㅆ다 at the end.
For example, 부르다 -> 불러요 -> 불렀어요.

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Summary

The following summarizes a table.

verb/adj.	르 irregular	르 irregular's past tense
모르다	몰라요	몰랐어요
빠르다	빨라요	빨랐어요
자르다	잘라요	잘랐어요
오르다	올라요	올랐어요
부르다	불러요	불렀어요
흐르다	흘러요	흘렀어요