BATED BREATH

 

Some people mistakenly write "baited breath" for "bated breath": "We watched with bated breath as the runners approached the finish line." That is, with breath drawn in or held because of anticipation or suspense. Of course, and per usual, bilingual people have an advantage because they can fall back on the Spanish "estar en ascuas, con el corazón en un puño, conteniendo el aliento", for example. Add this idiom to your list, and use it.