Translation

• to be at home
• (at a workplace) to be in (as opposed to being away on official business 出差[chu1 chai1])
• (Buddhism etc) to remain a layman (as opposed to becoming a monk or a nun 出家[chu1 jia1])

Examples

• 你的母亲现在在家吗？
  Is your mother at home now?
• 你在家里吗？
  Are you at home?
• Ken昨天在家吗？
  Was Ken at home yesterday?
• 你母亲在家吗？
  Is your mother at home?
• 现在我爸爸不在家。
  My dad is not at home for the moment.
• 他明天会在家。
  He will be at home tomorrow.