Some word confusions are interesting but not quite common enough
to qualify for an entry on my Common Errors in English Usage Web
site. Some seem nevertheless worth discussing here. “Berth”
originally referred to the room required by a ship to maneuver
freely, later to the space within which a ship could anchor
itself near the shore. Hence the expression “to give a wide
berth,” meaning to stay well away from someone or something.
Then it was sailors rather than ships who were berthed: a place
for a sailor to sleep was a berth. And to have a berth was more
broadly to have a place—a job—on a ship. Finally, the term came
to be applied to athletics, where a contestant is assigned a
berth: a spot in a contest. A basketball team is assigned a
berth in the Final Four. The stacked beds in railroad sleeper
cars and bunks are also referred to as berths. Since most people
now encounter the term in connection with sports, they sometimes
misspell it as “birth.” You will also occasionally see people
saying they give someth