Spanish > English
en serio
1. adv. seriously, really, for real, in earnest, on the level
Analysis
en
1. prep. in, at, on
Estoy en casa. - I'm at home.
Estoy sentado en la computadora. - I'm sitting at the computer.
en esta página - on this page
en la caja en la mesa - in the box on the table
serio
1. adj. serious, earnest, sober, solemn (without humor)
2. adj. serious, grave, deep (important, weighty)
3. adj. serious (really intending what was said)
4. adj. straight (demeanor)
Mi culpa. Solo no podía mantener la cara seria por mucho tiempo. Era imposible. - My bad. I just couldn't keep a straight face for very long. It was impossible.