1. Introduces a conditional clause
   "I will go to university if I can afford it" 
2. Despite being
   "he's nice, if rather patronizing" 
3. Every time that
   "if I call you are always engaged"
   - whenever, when

Encyclopedia: If

• science fiction
• science lab
• science laboratory
• science museum
• science teacher
• scient
• scienter
• sciential
• scientific
• scientific agriculture
• scientific discipline
• scientific fact
• scientific instrument
• scientific knowledge
• scientific method
• scientific research
• scientific theory
• scientifically
• scientism
• scientist
• Scientology
• scilicet
• scilla
• Scilla nonscripta
• Scilla verna