I though you could leave the t off (ben) when using the second person of the singular
Only for "jij" and "je", not for the formal "u".
I tried looking up 'ouder' as a noun to see if it is de or het and Wellidwoord did not recognise it as a noun. Is it a de noun?
de, according to wiktionary
What an interesting sentence. Bent u een oudere? or Bent u ouder? has a very different meaning.
Seems strange that for "Ik heb een broer" I can't say "I have a brother" for but for this one I can say "I am a parent".
Silly question, but just curious: why not the very literal "Are you an elder"?
That would be, "Bent u een oudere?"
Presumably because it's a disguised adjective (een oudere mens)?