| knowledgeable(adjective, careful, cautious, aware, attentive) |
| not missing a trick(expression, adjective, idiom, alert, intelligent) |
| obedient(adjective, correct, alert, intelligent, attentive) |
| observant(adjective, kind, sympathetic, alert, careful) |
| observing(adjective, kind, friendly, careful, caring) |
| on the ball(expression, adjective, idiom, alert, careful) |
| on the job(expression, adjective, idiom, careful, knowledgeable) |
| on to(expression, adjective, careful, aware, attentive) |
| penetrating(adjective, correct, alert, intelligent, attentive) |
| perceptive(adjective, alert, intelligent, attentive, watchful) |
| plugged in(expression, adjective, sympathetic, careful, aware) |
| questioning(adjective, correct, alert, intelligent, attentive) |
| quick(adjective, alert, intelligent, perceptive, attentive) |
| respectful(adjective, careful, knowledgeable, cautious, aware) |
| searching(adjective, correct, alert, intelligent, attentive) |
| sensible(adjective, careful, knowledgeable, cautious, aware) |
| sensitive(adjective, kind, friendly, alert, caring) |
| sharp(adjective, alert, intelligent, perceptive, attentive) |
| sharp-eyed(adjective, correct, sympathetic, alert, intelligent) |
| solicitous(adjective, kind, friendly, careful, caring) |