IMAGE CREDIT: ADAPTED FROM CAREERS360.COMI think the statement about contest requirements that you used to hear when you were growing up, and then the one you heard lately, are both grammatically and semantically defective:
1. “Open to ‘18 years old and above’ only.”
2. “Open to ‘18 years old and older’ only.”
The construction “18 years old and above” is grammatically awkward and bad-sounding; even worse, the construction “18 years old and older” is a grammatical abomination that should be avoided like the plague, so to speak.
Both of the statements you heard will make sense only if they are prefaced by a proper subject for the age requirement—the “contest” or “contest participants.” We can then fine-tune the statement in any of the following three ways:
1A. “This contest is open only to participants who are at least 18 years old.”
2A. “Contest participants must be at least 18 years old.”
3A. “Contest participants must be at least 18 years old to join.”
The qualifier “only” may be used in Statement #1A to emphasize the minimum age requirement, but “only” is actually optional and can be dropped without changing the sense of that statement: “This contest is open to participants who are at least 18 years old.”
Statements #2A and #3A absolutely don’t need the qualifier “only.” This, to my mind, is why both the two versions you heard and wondered about are grammatically and semantically flawed—aside, of course, from not having a clear subject to make them sound right.
