Hi! I don’t really get the difference between ないで and てはいけない. Don’t they both mean “don’t” as in “don’t do that.”?
Can I say 風邪を引いてはいけないよ？
Thanks guys!
1 Like
I have little real-world experience, so take this with a grain of salt.
ないで is like て-form but for negative (at least in the case I think you care about right now). てはいけない is more like saying you must not do something.
I feel like the difference is that ないで is someone giving their personal opinion to not do something (“don’t do”). But てはいけない is more like there is some reason outside of themselves for saying not to do something (“mustn’t do”; maybe it’s not acceptable culturally or whatever). I’m sure @mrnoone can explain the difference better (or correct me if I’m making any mistakes).
「愛してる」と言わないで: Don’t say “I love you”
Maybe in this case you just said 愛してる and the person you said it to rolled their eyes and responded with 「愛してる」と言わないで.
「愛してる」と言ってはいけない: You must not say “I love you”
Maybe in this case you are getting advice from your friend about whether it’s okay to say “I love you” to someone, and they are saying you must not say that (because it’s culturally unacceptable or something like that). I imagine they could also use 言わないで in this case.
I’m coming up with this example on the spot, so it may not be perfect.
As for 風邪を引いてはいけないよ, to me that sounds like you are saying it is unacceptable/forbidden for this person to catch a cold. I don’t really think it makes sense.
I might say something more like 風邪を引かないでね (but again, don’t just take my word for it).
2 Likes
IIRC what I was teached about this matchs what @seanblue says, being naide a way of saying “please don’t…” against tehaikenai being a way of saying “it is forbidden/not allowed to…”