to watch someone carefully because you don’t trust them completely
observar a alguien cuidadosamente porque no confías completamente en él (observar a alguien cuidadosamente porque no confías completamente en él)
"I’ll keep an eye on him while you’re away."
"Voy a mantener un ojo en él mientras no estás." (Voy a **mantener un ojo en él** mientras no estás.)
a decision or opinion has not yet been reached
to move something to an earlier time
to reduce the time needed for something
to create a positive image of yourself in someone's mind
to surprise or shock someone suddenly
to be the best or most successful in a situation