How I distinguish verb conjugation groups

In this lesson, I will introduce you the typical way how we Japanese native speakers distinguish verb conjugation groups.
You can tell whether a verb is a う-verb or a る-verb by conjugating the verb into negative plain forms, which is ない forms.

If you can hear the vowel あ(a) before ない(nai), it is a う verb.
If you can hear the vowel either え(e) or い(i) before ない(nai), it is a る verb.

<Examples of う verbs>
Dictionary Form: かく(kaku)
Negative Plain Forms: かかない(kakanai) 

Dictionary Form: はしる(hashiru)
Negative Plain Forms: はしらない(hashiranai) 
* When you can hear the vowel あ(a) before ない(nai), verb conjugation group will be う verb.

<Examples of る verbs>
Dictionary Form: たべる(taberu)
Negative Plain Forms: たべない(tabenai) 

Dictionary Form: みる(miru)
Negative Plain Forms: みない(minai) 
*When you can hear the vowel either え(e) or い(i)before ない(nai), verb conjugation group will be う verb.

References:
Verb Conjugation
https://anchor.fm/yuya-sato/episodes/Verb-Conjugation-emv716

Present Tense Conjugation
https://anchor.fm/yuya-sato/episodes/Present-Tense-Conjugation-en0a2r

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