= Maggie sensei, kyou no ressun, yabakattassu!
= Miss Maggie! Your lesson today was totally awesome!
= Narenareshii naa…
= He is way too casual with me!
Today’s slang is 「タメ口」( = tameguchi) a casual talk, to talk like equal friends.
*タメ口を効く ( = tameguchi wo kiku)
( = Kare wa sensei ni tameguchi wo kiite ita.)
He was talking to his teacher too casually.
= tameguchi /tamego de hanasu
Note : タメ語 ( = tamego) is slightly newer than タメ口（ = tameguchi) but it has been used equally now.
*タメ口 or タメ語を使って話す ( = tameguchi /or tamego wo tsukatte hanasu.)
Ex *タメ口/タメ語でいいよ 。
= Tameguchi／Tamego de iiyo.
= You can talk to me (more) casually.
They all mean to talk to someone very casually like a close friend.
タメ ( = tame) means “equal”.
(Note : It is originally from a dialect and it means 同級生 ( = doukyuusei) peers, classmates, the same year students.
Japanese school has 先輩 ( = senpai) senior students 後輩 ( = kouhai) junior students relationship and you are supposed to use 敬語（ = keigo) honorific language towards 先輩 ( = senpai) senior, older students .
タメ口 ( = tameguchi) /タメ語 ( = tamego) are なれなれしい言葉使い ( = narenareshii kotoba zukai) too familiar way of talking
なれなれしい・馴れ馴れしい（ = narenareshii)＝too familiar, too friendly, too casual
Related word : 遠慮がない ( = enryo ga nai hito) no reservation
(→See 遠慮 ( = enryo) lesson!)
For example, if you have just met a person and he talks to you as if he were your old friend, you might naturally feel a little uncomfortable.
= Kare wa shotaimen nanoni narenareshii
= I just met him for the first time but he behaves or talks to me like we were buddies.
Or when someone talks to you in a way that you find to be too friendly or touches you too much as if you were very close, you can tell that person,
= Narenare shiku shinai de!
= “Don’t get fresh with me!”
So what kind of talk is タメ口 ( = tameguchi)?
See the picture above!
= Maggie Sensei, kyou no ressun, yabakattassu!
= Maggie Sensei, your lesson today was totally awesome!”
やばい、ヤバい ( = yabai) or ヤバ! ( = yaba!) is a very casual expression.
It is originally a very vulgar term meaning risky or dangerous.
If , for example, a criminal sees a police coming, he might say,
= Yabai! Satsu ga kita!
= “Oh shit! Here come the cops!
Note ：サツ ( = satsu) is a derogatory term for 警察 ( = Keisatsu) police.
= Aitsu yabai kara amari chikazukanai hou ga iiyo.
= He is very dangerous so you’d better stay away from him.
But lately it is used in more casual way like ”Oops!”
= Yabbaaaa… Shukudai wasurechatta!
= “Oh damn! I forgot my homework!”
Also, we used it when something is GREAT or DELICIOUS!
= Kore yabaiyo!
= The literal meaning is, “This is dangerous!”
“This is REALLY yummy!” /”This is awesome!” /”This is remarkable!”
You might think it’s confusing because we use this word as “dangerous” and “great”. You just need to figure it out by its context. You may notice that yabai and maji are overly used among young people or TV personalities nowadays…
Variation : This is really casual but you can also hear or see in “Japanese anime“「やべっ！」( = Yabe!) 「やべ〜!」 ( = Yabee) ”Oops!””Oh-No…”
One more point from the phrase.
= kyou no ressun yabakattassu!
=“The lesson today was totally awesome!”
You see the odd ending 「っす」 ( = ssu) ?
The original sentence should be:
= Kyou no ressun totemo omoshirokatta／subarashikatta desu)
There is a tendency to finish the sentence with 「〜っす。」( = ssu) instead of 「〜です。」( = desu) especially among young boys. They try to speak politely by using this 「〜っす。」( = ssu) ending.
= Kore wa kimi ga yattano?
= “Did you do this?”
= “That’s right!”
(←「そうです。」( = Soudesu))
= “That’s not right!”
= Okusan no ryouri yabaissu nee.
= ”Your wife’s cooking is incredible!”
= Okusama no oryouri oishii desu nee
As other slangy expressions, be careful when to use this, OK?
= Kono burogu ni kite kureru h ito wa mina watashi ni tameguchi de hanashite moratte iidesu karane.
= All of you who visit this blog can talk to me casually, OK?
= Kyou no ressun chotto yabakatta?
= Is today’s lesson “awesome”?