Yesterday, when talking about 偉い (erai), I got to thinking about another word that confuses me at times:

大した
tai shita
great; wonderful; marvelous; superb; fabulous; extreme; extraordinary; exceptional; enormous; immense; considerable; a great [good] deal of….

I'm starting to see why dictionaries confuse me so much...

The way that I most commonly hear this word is in this phrase:

大したことない
tai shita koto nai
No big deal.

You see it a lot in anime and manga, for example, when a character is trying to say something's no big deal, nothing special, nothing to write home about, etc.:

(I think maybe this is from 進撃の巨人 [shingeki no kyojin]?)

そして考えろ
soshite kangaero
Then think of something.
(Literally: "then + think [command].")

お前のその大したことない頭でな
omae no sono tai shita koto nai atama de na
Using that tiny brain of yours.
(Literally: "your + that + nothing special + head + with [で] + な.")

死にたくなきゃ　必死に頭回せ
shinitakunakya hisshi ni atama mawase
If you don't want to die, start thinking fast.
(Literally: "if you don't want to die + frantically + head + spin [command].")

Perhaps this goes without saying, but you should probably avoid telling anyone that they have a "nothing-special head," a 大したことない頭 (tai shita koto nai atama).

If you're in a traditional Japanese classroom, your teacher might even correct this phrase when you use it.

I'm pretty sure when I first saw 大したことない (tai shita koto nai), it was in a textbook, in one of these much more polite forms:

#1
大したことではない
tai shita koto de wa nai
be nothing to brag about; be nothing to write home about; be of no matter; count for little

#2
大したことではありません
tai shita koto de wa arimasen
be nothing to brag about; be nothing to write home about; be of no matter; count for little

#2 is a bit more formal than #1, and both are more formal than the particle-free version you'll often hear in casual conversations, 大したことない (tai shita koto nai).

Sudden surgical breakdown of this phrase:

大
tai
big

した
shita
did; done; made

こと
koto
thing

(では) / では
de wa
[evil particles]

ない / ありません
nai / arimasen
is not

"Big done thing is not" --> "No big deal"

Or something like that.

But we don't have to stick こと (koto) onto 大した (tai shita)...

Other Uses of 大した

I'm not super skilled at using 大した in other ways.

For example, this one time, I read this phrase in HUNTER X HUNTER:

とぼけてんなら
大した嘘つきだわ
toboketen nara
tai shita usotsuki da wa
If he's just playing dumb,
he's a hell of a liar.

(Literally, Line #1: "is pretending not to know + if")
(Literally, Line #2: "great + liar + is + わ")

(Note: とぼけてん = とぼけている. The verb とぼける means "to play dumb; to feign ignorance.")

So I read this phrase in a manga, then later on, I jokingly repeated this phrase to Rei:

大した嘘つきだ（ね）
tai shita usotsuki da (ne)
You're such a liar. // You're a hell of a liar.

I thought it would sound sarcastic... funny, even.

Nope.

She got really offended.

That's what I get for learning from a rude, murdering, manga character, I guess...

I should just leave teaching to the native speakers.

Which is why I had Rei pick out some photos and phrases for us using 大した (tai shita)...

大丈夫、大したケガじゃないよ。
daijoubu, tai shita kega ja nai yo.
I'm OK. This is just a scratch.
(Literally: "OK + great + injury + is not + よ.")

(Note: Actually, my jaw is broken, and I've lost a lot of blood... but I'm alive!)

あなたのゴルフの腕前、大したものですね。
anata no gorufu no udemae, tai shita mono desu ne.
Your golf skills are thoroughly impressive.
(Literally: "your + golf + の + ability/skill + great + thing + is + ね.")

(Note: I don't think I could have produced this sentence very well in a conversation. I should probably practice/review my own lessons *_*.)

ライオンも大したことないな。
raion mo tai shita koto nai na.
I could take on a lion, no problem.
(Literally: "lion + also + great + thing + is not + な.")
(Note: I don't know why Rei has to choose my most dufus of photos.)

Bonus Phrases

進撃の巨人読んだことある？
しんげきのきょじん　よんだ　こと　ある？
Have you ever read Attack on Titan?