adjective (a)

• (often followed by `to') giving care or attention(adj.all)

  Example:
  Attentive to details.
  The nurse was attentive to her patient.
  An attentive suitor.
  

  Antonym:
  inattentive
  

  source: wordnet30
• taking heed; giving close and thoughtful attention(adj.all)

  Synonym:
  heedful, paying attention, thoughtful
  Antonym:
  heedless, unheeding
  

  source: wordnet30
• Heedful; intent; observant; regarding with care or attention.(adjective)

  source: webster1913