Add spaces: Debianinvitesyoutoits20thbirthday

Answer: Debian invites you to its 20th birthday

Add spaces: ButbuyachildatoyTamagotchiwasquiteexpensiveformany.

Answer: But buy a child a toy Tamagotchi was quite expensive for many.

Add spaces: Eachbedroomhasitsownbathroom.

Answer:
Each bedroom has its own bathroom.