When visiting Delhi, it's always helpful to know a few basic phrases in Hindi, the local language. Some common phrases to remember include 'Namaste' as a greeting, 'Shukriya' for thank you, and 'Kitna hai?' for asking about the price. You can easily learn these basic words and expressions by using language apps like Duolingo or Babbel, or by taking a short language class at a local institute. This will greatly enhance your experience and interactions with the locals.