LEARN + JAPANESE / Note 81 JLPT N5
May I? You Mustn't (てもいい・てはいけない)
てもいい attaches to a verb’s て-form to mean “may, it’s okay to.” てはいけない attaches the same way to mean “must not, it’s forbidden.” Same て-form both directions, opposite permission.
Teacher, may I use a dictionary?
Is it okay if the homework is tomorrow?
In Real Life
てもいい literally reads “even if [you] do this, it’s good,” も carrying its “even” meaning from Anyone, Anytime, Anywhere straight into this construction. Asking permission with か on the end is the standard, polite way to check before doing something.
You must not turn in homework by email.
Do I have to work on weekends too?
In Real Life
てはいけない is a flat prohibition, stronger than simply saying you don’t want to do something. なくてはいけない (the negative te-form plus はいけない) flips the meaning to obligation instead, “not doing this isn’t allowed,” which lands as “you have to.” Negating a negative to state a requirement is a pattern that shows up constantly in Japanese.
Vocabulary
| Japanese | English |
|---|---|
| dictionary | |
| katakana | |
| homework | |
| bright, cheerful | |
| personality | |
| voice | |
| suit | |
| plate, dish | |
| to wash | |
| during the morning | |
| transportation costs | |
| by oneself | |
| to pay | |
| to permit, allow | |
| to prohibit | |
| school rules | |
| rule, regulation | |
| to allow, forgive | |
| obligation, duty | |
| freedom |