Where does the apostrophe goes if the sentence shows ownership?

Find the owner. The owner may be singular or plural. Put the apostrophe straight after the owner. If the owner is singular, then add an S.

For example: the dogs breakfast. Who owned the breakfast? If it was the (one) dog, then write the owner (the dog), add the apostrophe AFTER it (the dog') and then put an s after that (the dog's). Correct sentence: "I made the dog's breakfast."

If the owner of the breakfast was several dogs, then write the plural owner (the dogs), then add the apostrophe AFTER it (the dogs'). You don't need another S. Correct sentence: "I made the dogs' breakfast."

Other examples:

• After breakfast I made the children's beds. (several children)
• After lunch I painted the dog's kennel. (one dog).
• After school I went to the teachers' office. (several teachers)
• After school I went to the principal's office. (one principal)

There is an exception: If a singular owner ends in an S, you usually do NOT add another S after the apostrophe (Mr Jones' car. Jesus' teachings. James' hat.)