On a completely unrelated note, I was thinking that it's about time for me to write up a post on 気 (ki).
気 can be translated in a number of different ways, depending on its usage - spirit, energy, life force, mood, etc. Just as the word itself has several meanings, so is it used in a ton of different expressions. So many, in fact, that I'm not going to attempt to list them all. I did want to jot down a few of the more commonly-used ones, however. And then if any of you have any favorites that I haven't mentioned, I invite you to share them in the comments.
1. 気をつける - 「きをつけて！」is an oft-used expression telling someone to be careful or to take care. You'll often hear it used when parting from a group of friends (or maybe coworkers after a drinking party) in the evening. Kind of like saying "Have a safe trip home!"
2. 気がつく - to notice. Sometimes this one can be used in one of the same ways as わかる. If you're not so observant, you'll want to condition your tongue to saying 「気がつかなかった」.
Ex: How much is all you can drink? I didn't notice a price.
3. 気がする - to have a feeling about something or to feel ~. I didn't start noticing this one until recently for some reason, and I get the feeling its usage is a little more broad than simply to "feel." Still, that seems to be the primary use.
Ex: I have a feeling I'm gonna lose.
4. 気になる - to be on one's mind or to be anxious about. This is also one feel I've not employed to the fullness of its potential. You can use it to say that you're interested in something (or someone) or that you're worried or uneasy about something.
Ex: Recently I've been interested in that restaurant since I always pass by it but have never been there.
So how about it? There are plenty more 「気」 phrases out there. What are some other good ones?