Adjective (い)
Expression
Usually written in kana
1. bad; wrong; naughty
いけない子です。You're a naughty child.
2. must not (do, be); should not; ought not to
after the -te form of a verb or adjective
だから、帰らないといけない。That's why I have to go home.
3. useless; no good; bad
ところがそれもいけなかった。But that was no good either.
4. hopeless; beyond hope
5. unfortunate; a shame; a pity
used to express sympathy
6. unable to drink (alcohol)
7. so as not to ...; so that ... (won't); in case ...; for fear that ...; lest ...
as ...（すると／しては）～（から／ので）