advertent, agog, alert, all ears, all eyes, apt, assiduous, attentive, aware, careful, concentrated, conscious, decisive, diligent, earnest, expeditious, finical, finicking, finicky, heedful, immediate, instant, instantaneous, intense, intent, intentive, meticulous, mindful, nice, niggling, observant, observing, on the ball, on the job, open-eared, open-eyed, openmouthed, prompt, punctual, quick, ready, regardful, speedy, summary, swift, watchful