This commit fixes mispellings of "occurrence" introduced by:
- 76a3b350ce (#17337)
- 8e8bea9044 (#17339)
and adds the same "every occurrence of" in the `replaceWord` func.
Other changes:
- Prefer "replace with" to "replace by".
- Be more consistent with "the" - prefer "of the character" given that
we wrote "by the character".
- Try to be more consistent with writing the types - add
"the string `sub`" given that we wrote "the character `sub`".
b70e33f5bb