A very difficult japanese derogatory sentence, very difficult to translate in derogatory english (for a non native at least…), but let’s try
That dude f*cking tell me that brat ain’t there again
edit: ok, completely mistook “いらん” for “いない”…
Once again that brat went and told me something I didn’t need to hear
また あのガキ
again, that brat - so far so good
教えやがって いらんこと
this is where it gets interesting:
the 〜やがって is a verb ending that indicates feelings of being offended, slighted, pissed off, etc.(depending on the context this could end up translated as seriously foul language e.g. yakuza films) I think the whole translation really hinges on this sense of frustration or anger the speaker feels. To convey it in English I added the “once” to “again” for extra emphasis and then the “went and told” for a passive sense of having something negative done to oneself.
いらんこと is literally unwanted or unnecessary thing(s), told to the speaker. In other words “things he didn’t need to hear”. I chose “hear” but could also be “know”
I was going to join in for the first time, but didn’t understand this at all.
may contain spoilers:
Is the phrase supposed to contain ないこと, as in ‘verb to noun’ (neg’ in this case), which is the grammar point linked above (and written on) the image? こと seems to be being used as ‘thing’ according the other translations.
Hi Steve, this is something called nominalization in English. The ‘noun’ isnt actually one word, but a group of words. いらんこと is slang for いらないこと (unneeded things). In this case ‘unneeded things’ is the ‘noun’.
Reply may contain spoilers:
Thanks Asher. I’m aware of こと for nominalization, but couldn’t see the neg verb being used. I thought it may have been いらない but wasn’t sure (the slang threw me off), and after looking at other translation it seemed everyone was going for いらん (unneeded) + こと (thing), I still couldn’t specifically see the neg verb + こと.
That’s really just down to my in-experience though, so all good. Maybe tomorrow 
こと seems to be being used as ‘thing’
こと (事) means thing (in an abstract sense).
The way that “verb to noun” works is that こと is the noun and we are describing it with a verb.
Keeping it as “thing” in the resulting translation can be kind of awkward which is why you don’t see it done in the example sentences for the grammar point (though the notes for one of them uses “something”). The reason why I think “thing” is showing up for today’s translation is related to how “いらん (いらない)” is a verb in Japanese, but “unneeded” and “unwanted” are adjectives in English.
ok yeah that helps clarify what’s going on a little better, especially for this particular phrase.
Thank you for the extra explanation.
September 6th Translation
Notes :
That damn やがる and しまう are damn actually pretty damn similar! While these two grammar points are not usually associated, we find that they actually blend pretty well together. They both regularly have the nuance of a minor amount of swearing (like the first sentence I wrote here), but しまう is usually aimed toward accidental things, where やがる is aimed toward things that someone purposefully did. In negative situations, this is the main difference. しまう can also be used in positive situations, but those cases are far less common.
常時スイッチを切らずに換気してください。
Ventilate without turning off the switch at all times.
I believe this would posted near an A/C control panel, asking users to leave the ventilation fan on at all times.
First attempt, here goes:
Translation
“Always use ventilation without turning off the switch”
Use:
消費期限を確かめずに牛乳を飲みました
常時スイッチを切らずに換気してください。
常時 = 1. Usually; Ordinarily; Always
スイッチ = switch
を = particle (indicates direct object of action)
切らずに = To turn off (e.g. the light) = 切る + without doing
に = probably for (purpose) usecase
換気 = Ventilation
して = て-form of する
ください = Please (do for me)
Rough : Please don’t turn off always-on switch for ventilation.
Natural : Please don’t turn off the always- on switch for ventilating [the room]
Note : I feel like this would hang next to a switch to keep in a room that has no natural ventilation flow, so it would have to rely on A/C for airflow, that’s why I added [the room].
Please turn on ventilation without turning off the light switch that always turned on.
I think this would posted near some double switch. First key would toggle light and another one toggle some ventilation fan. And the light key should always be on.
@Asher by the way, what’s 関西弁 for いない？「いん」？
So I’m taking this is a Kansai-ben example and not 違乱 like I had assumed. Now that I’m looking this up, this is a very famous Kansai manga so that makes more sense now. Would be great to get a heads up if this is the case, maybe others are used to dialect examples but I’m still pretty terrible. Anyone care to share what choices for standard would look like here?
Please ventilate without cutting off the timer switch.
I believe this is a toilet sign w/ fancy Japanese bathroom technology and this relates to 常時換気タイマスイッチ but shortened
ちゃんと朝ご飯を食べずに早くに出なくてはいかなかった。
I’m not sure about the relation to 関西弁 but I took it as just shortened slang for the negative of 要る, like how in anime/manga you’ll see 分からない become shortened to 分からん. I’ve also seen じゃない shortened to じゃん often.
It seems to only happen in godan verbs that end in る (like 分かる, 知る, 要る).
Here’s a post on Japanese StackExchange with a little more info:
Also - one commenter (on the original question, not the answer I linked) said that it’s common everywhere not just Kansai-ben, so perhaps also it’s not related to just anime/manga like I suggested.
Common switch
Turning off (the light?)
The ventilation, please.
Please do not cut the ventilation when turning out the light.
I am really struggling here --’
You’re not the only one, I promise. 
This sentence took me a bit to decipher just because it doesn’t seem to translate naturally. When I have trouble with one of the sentences here are a few things I do to help:
Type the sentence out first and use rikaikun or Yomichan to hover over and check the words I don’t know.
I was confused about 常時. The definition from rikaikun says it can be a noun or an adverb.
The 常時 right against スイッチ is a little strange, I couldn’t tell if it was “continuous switch” or, if the 常時 was acting as an adverb like at “at all times”.
So then I use this website to search for a sentence that contains the part that I’m struggling with.
https://sentencesearch.neocities.org/
In this case, the only example for 常時 was translated as “at all times”.
常時、救命胴衣を身に付けて下さい。
Wear your life jacket at all times.
I also check jisho.org for examples.
The example sentence on Jisho for 常時 is this:
彼は常時彼の才能をねたむ人々から中将されることにうんざりていた。
He was sick of being vilified all the time by people who were jealous of his ability.
So I decided to go with “at all times” for my translation instead of “continuous switch” or “common switch”.
Sorry it’s a little wordy but hopefully this helps someone. That Sentence Search website comes in handy quite a bit!
Great to discuss, this more common than I realized. 
I don’t know the specific etymology, or it matters. Sampling some native responses from Kansai-Chubu-Kanto region, they will hear and use it. But I asked a native from Tohoku, they would not use it…but then someone from Kyushu may use it as well (!). So seems everyone know what it is though but I believe いらない and 分からない are still considered ‘standard’ but this appears too common not to learn.
If curious, here were a few native responses in regards to いらん and わからん. For simplicity of a non-native asking, they say Kansai-ben but still used in various places.
Then interestingly, another native saying it is or less used but think it is Nara-ben (いらん) which I guess is just overall Kansai-ben. There is a whole thread of responses from different areas saying they use it.
For ventilation please keep the power switch on at all times
常時スイッチ - I think this can be broken up into either a noun (常時スイッチ) or adverb(常時) + noun(スイッチ). So it’s either : always/at all times, the switch or the always-switch.
を切らずに - this grammar pattern indicates the sense of without doing X. So without cutting/turning off the always-switch. Or always/at all times without turning off the switch(I’m leaning towards this interpretation. In my translation I inverted this into the positive sense of keeping it powered on for the sake of clarity and naturalness)
換気して - do ventilation. This needs to be converted into more natural English so I went with “for ventilation”
ください - please 
It’s nice that they ask so politely
