Embarrassment

Quedarse/estar cortado/a (*) Lit. To be left cut/To be cut. To lose one's nerve/tongue (out of embarrassment).
Intenté hablar con ella pero me quedé cortado (*) I tried talking to her, but embarrassment stopped me.

Ser un/a cortado/a (*) To be a very shy and embarrassed person.
Para esas cosas soy muy cortada (*) I'm very shy about that sort of thing.

(No) tener cojones/huevos (**) Lit. To (not) have the testicles/eggs. To (not) have the balls.
¿A qué no tienes huevos para decírselo? (**) I bet you don't have the balls to tell him.

Acojonarse (**) To get/have your balls in your throat (from fear).
El examen de conducir me acojona mogollón (**) The driving test scares me to death.

Cf. Cojones

Happiness

Estar como unas castañuelas (*) Lit. To be like some castanets. To be very happy.
María está como unas castañuelas con su nuevo novio (*) María is as happy as a clam with her new boyfriend.

Estar loco/a de contento (*) Lit. To be crazy with happiness.
Están locos de contento con el bebé (*) They are delighted with the baby.

Sadness

Un bajón (*) Lit. A big drop, for example when travelling on a plane. Figuratively, a downer.
Le ha entrado un bajón desde que rompieron (*) He's been on a downer since they split up.

Depre (*) Short for depresión. Used when you're heading for depression but not quite there yet.
Ser (un/a) depre (*) is to be a pessimist.
Es un tío depre - siempre contando sus penas (*) He's a pessimistic bloke - always talking about his problems.
Estar depre (*) To be down.

Confusion

Estar zombi (*) Lit. To be like a zombie. To be scatterbrained, to think or act aimlessly.
Hoy no puedo concentrarme, estoy zombi total (*) I can't concentrate today - I'm completely scatterbrained.

Estar en Babia (*) To have your head in the clouds. Babia was the retreat of early Castilian kings in the Middle Ages: when they were there, they didn't have a clue what was going on.
Es un incompetente total, siempre está en Babia (*) He's completely incompetent, his head's always in the clouds.

Madness

Tener un cacao mental (*) Lit. To have cocoa in your mind. To have your mind in a mess. Cocoa needs a lot of stirring, hence the feeling in your head.

Estar como una cabra (*) Lit. Like a goat. Figuratively, mad as a hatter.
Se quiere ir a vivir a Siberia - está como una cabra (*) He wants to go and live in Siberia - he's mad as a hatter.

Faltarle un tornillo (*) Lit. To be missing a screw. To have a screw loose.
¿Para eso llamas a las dos de la madrugada? ¿Y a ti qué tornillo te falta? (*) Is that why you're ringing at 2am? You got a screw loose or something?