While reading Tae Kim’s grammar guide on obligation, I got confused about how the polite forms of いけない and ならない are formed.
Examples:
- ここに入ってはいけません
- 早く寝てはなりませんでした
Tae Kim says these conjugate like i-adjectives, but I don’t see why:
- いけない becomes いけません
- ならない becomes なりません
Why does け stay the same, while ら changes to り? What rule explains this?
I hope someone can resolve my confusion. Thanks in advance.
by you_got_a_minute