THESAURUS
johnny on the spot
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
