When should I use "eldest" and when should I use "oldest"?
Are the differences semantic or regional? (Or both?)
Indeed, both eldest and oldest refer to the greatest in age. The crucial difference, however, lies in the fact that eldest can only be used for related persons, while oldest can be used for any person, place or thing in a group of related or unrelated elements. Examples:
And while eldest can be used for any group of related persons, in reality, it is mostly only used in reference to siblings.
New Oxford American Dictionary (2nd Edition) definition of eldest:
They are interchangeable; they both mean exactly the same thing. I think there is a general tendency to use eldest in relation to people, e.g.
For some reason,
sounds wrong, almost like he's the son you've had for longest as opposed to him being the son with the greatest age.
Both are okay. Just elder, eldest are often used to replace older and oldest, nowadays.
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