While I believe it’s a good idea to learn fundamentals of a language in a relatively formal setting like a classroom or at least using a textbook, often expressions that are considered slang will be omitted or deemphasized in those forums. That’s why I think it’s good to actively seek out slang expressions that you can be prepared to hear from native speakers in more informal settings.
This time I’d like to go over the word “yosage”, which is generally written as 良さげ but it can also be written in pure hiragana as よさげ.
Judging from the kanji “良” you might guess this phrase has something to do with being “good”, and you’d be right. It turns out that 良さげ means something along the lines of “seems to be good”.
Coincidentally, saying “seems to be good” in Japanese is actually a little tricky because it is an irregular word. Normally you can use the suffix 〜そう after the root form of an i-adjective to express “seems like ~”. For example 寒そう (samusou) would mean “(it/that) seems cold”.
However, “よそう” (or 良そう) would be incorrect (though there is a word よそう that means something completely different, “expectation”). It turns out that 良さそう (yosasou) is actually the typical way to say “(it/that) seems good”, though there are other phrases like いいみたい.
So where did 良さげ come from? Well, sometimes げ can be used at the end of a word to convey “like ~” or “looking ~”, as in the expression 悲しげに (kanashige ni) which means “looking sad” (this げ can be written with the kanji 気 but I haven’t seen that too frequently in modern Japanese). Having said that, grammatically you would expect to see 良げ, not 良さげ, so that doesn’t quite fit. I’ve heard that 〜げ is used in some regional dialects as well, but it’s unclear if this phrase derives from those.
In any case, what is clear is that this phrase is considered colloquial and used primarily by younger speakers. I haven’t ever seen it in formal writing either. I will say that it feels a lot easier to say 良さげ instead of 良さそう, probably because of the latter’s double “s” sound.
As for the usage, you can use 良さげ just like you would use any other na-adjective. For example:
- 良さげな本を買ってきました. (yosage na hon wo katte kimashita)
- I bought a book that looks good.
If you want to learn a little more about this word you can see this interesting thread in Japanese about people asking where it came from.