| obedient(alert, intelligent, perceptive, attentive, watchful) |
| observative(alert, intelligent, perceptive, attentive, watchful) |
| on alert(expression, keen, anxious, alert, careful) |
| on one's toes(adjective, awake) |
| on the |
| on the watch(expression, adjective, idiom, alert, careful) |
| on toes(expression, keen, sharp, careful, alive) |
| penetrating(alert, intelligent, perceptive, attentive, watchful) |
| perceptive(sharp, bright, lively, alert, intelligent) |
| prepared(adjective, alert, careful, cautious, aware) |
| psyched up(expression, adjective, sharp, bright, lively) |
| questioning(alert, intelligent, perceptive, attentive, watchful) |
| qui vive |
| quick-witted |
| regardful(alert, intelligent, attentive, watchful, sharp-eyed) |
| responsive |
| searching(alert, intelligent, perceptive, attentive, watchful) |
| see after(expression, adjective, alert, careful, cautious) |
| see to(expression, adjective, alert, careful, cautious) |
| sensible |