Old Naming Patterns

The first son was named after the father's father.
The second son was named after the mother's father.
The third son was named after the father.
The fourth son was named after the father's eldest brother.
The first daughter was named after the mother's mother.
The second daughter was named after the father's mother.
The third daughter was named after the mother.
The fourth daughter was named after the mother's eldest sister.

Swedish Naming Patterns

If Olaf had a daughter that he named Inga would be named: Inga Olafsdotter (or Olaf's daughter).
If Olaf had a son that he named Sven, his would be called Sven Olafson.
When Sven has a daughter that he names Olga, Olga's name would be Olga Svensdotter.
Her brother Lars would be Lars Svenson.

German Naming Patterns

See this page.