1. Could not

Encyclopedia: Couldn't

• young bird
• young blood
• young buck
• young carnivore
• young fish
• young girl
• young lady
• young mammal
• young man
• young person
• Young Turk
• young woman
• Young's modulus
• young-bearing
• young-begetting
• younger
• youngish
• youngling
• youngness
• youngster
• Youngstown
• younker
• your
• yours
• yours sincerely