Declension tables are quite useful here. How can I type them? Is there non-painful way to type them?

As I was trying to write down the lyrics of a song (this one: https://youtu.be/7JrnFtvoGbc ), I realized that my English isn't good enough to understand everything properly. English not being my first language (that is German) may is contributing. The lyrics I have got so far are: It's your bir...