1-the baby was the PRINCIPLE reason for his happiness

2-the jury heard only the PRINCIPLE facts
3-It's not the facts that upset me,it's the PRICIPALS of the case
4-his hay fever was the PRINCIPLE reason for his sneezing
5-she was a person of strong PRINCIPLE

3 answers

Great! All are correct!
thank you for your nice words Ms. Sue:)
You're very welcome, Astasia.